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    Poster Session 1

    Room: Ballroom 100

    2022-07-29   16:00 - 18:00



    1.    AES Carrier Award  Tuning Guitarfishes of the Southwestern Indian Ocean: Redescriptions of Three Rhinobatos. Rachel Aitchison*, Pacific Shark Research Center, Moss Landing Marine Laboratories; David Ebert, Pacific Shark Research Center, Moss Landing Marine Laboratories; Simon Weigmann, Elasmo-Lab, Elasmobranch Research Laboratory   rachel.aitchison7@gmail.com

    Shark-like rays (Rhinopristiformes) are found worldwide and are among the most threatened species of cartilaginous fishes. The guitarfishes (Rhinobatidae) are one of five families in this order, with many species assessed as vulnerable or higher by the International Union for Conservation of Nature (IUCN). Current fisheries and conservation efforts are limited, however, due to unresolved taxonomic issues and poor species descriptions. Presently, there are three described species of Rhinobatos from the Southwestern Indian Ocean, Rhinobatos austini, R. holcorhynchus, and R. nudidorsalis. These three species of Rhinobatos are often mistaken for one another and are assessed as Data Deficient. Until it’s description in 2017, R. austini was misidentified with the poorly defined, offshore occurringR. holcorhynchus. Rhinobatos nudidorsalis was described from a single specimen caught near the Mascarene Ridge in 2004, but may have been previously misidentified as R. holcorhynchus. Since the descriptions of R. austini and R. nudidorsalis, additional specimens have become available and were analyzed using a linear discriminant analysis. Morphometrics from four additional congener species of Rhinobatos from the Indian Ocean were included and served as comparative material. Results show distinct clusters for species of Indian Ocean Rhinobatos and indicate that the oronasal region differentiates Southwestern Indian Ocean species. In addition, R. austini, R. holcorhynchus, and R. nudidorsalis are redescribed based on new material. These redescriptions provide taxonomic clarity for Southwestern Indian Ocean guitarfishes and will aid in species-specific identification, leading to improvements in conservation and fisheries monitoring and management.


    2.    AES Carrier Award  Diel Vertical Habitat Use of a Scalloped Hammerhead and Bigeye Thresher Shark. Taylor Anderson, University of Nevada; Emily N. Meese*, Texas A&M University at Galveston; J. Marcus Drymon, Mississippi State University; Greg W. Stunz, Harte Research Institute for Gulf of Mexico Studies, Texas A&M University Corpus Christi; Brett Falterman, Fisheries Research Support; Elias Menjivar, California State University Long Beach; R.J. David Wells, Texas A&M University at Galveston   emily.n.meese@gmail.com

    Understanding habitat use of elasmobranchs in pelagic environments is complicated due to the mobility of these larger animals and their increased distributions as they often cross multiple jurisdictional boundaries. Additionally, pelagic elasmobranchs often display oscillatory diving behavior, highlighting the importance of vertical habitat use of elasmobranchs to help assess current and potential interactions between critical habitat and anthropogenic activities. The scalloped hammerhead (Sphyrna lewini) and the bigeye thresher (Alopias superciliosus) are both targeted and taken as bycatch in coastal and pelagic longline fisheries and are listed as Critically Endangered and Vulnerable by the IUCN Red List, respectively. To better characterize the vertical habitat use of these vulnerable species, this study caught and electronically tagged a single male scalloped hammerhead (PSAT, 90 d and SPLASH tag, 22 d) and a bigeye thresher shark (PSAT, 16 d) in the northern Gulf of Mexico. The scalloped hammerhead occupied significantly deeper waters during the night than during the day (p < 0.001) while the bigeye thresher occupied significantly deeper waters during the day than at night (p = 0.005). The scalloped hammerhead experienced nighttime temperatures ranging from 15 – 28 °C, while the bigeye thresher experienced nighttime temperatures ranging from 10 – 28 °C. The scalloped hammerheads horizontal movements were restricted to the continental shelf. The contrasting diel vertical habitat use between these species could potentially be attributed to predator-prey interactions and thermoregulation behaviors, which can be coupled with fishery catch data to adjust management practices and improve future ecological risk assessments for vulnerable species populations.


    3.    AES Carrier Award  Immature Bull Shark Habitat Use and Residency in the Manatee River, a Non-Thermally Altered Nursery Area. Cecilia Hampton*, New College of Florida; Tonya Wiley, Havenworth Coastal Conservation; Jayne Gardiner, New College of Florida   cecilia.hampton18@ncf.edu

    The Manatee River is a non-thermally altered estuarine river that flows into the southern edge of Tampa Bay, adjacent to its connection with the Gulf of Mexico. Prior studies suggest that temperature and salinity are the primary environmental factors driving juvenile bull shark habitat use and that the duration of residency in the nursery may vary with latitude. However, previously-studied nurseries at latitudes similar to that of the Manatee River have all been in thermally-altered rivers (due to the presence of warm water discharges from power plants). The goal of this project was to examine immature bull shark use of this habitat in relation to natural seasonal variation in temperature and salinity. We deployed a network of acoustic receivers within the estuarine portion of the Manatee River to track the movements of acoustically-tagged juvenile bull sharks (n=30). Incorporating data from our own temperature/salinity loggers and data from USGS water quality stations, we modeled the hourly temperature and salinity at each acoustic receiver station in the river as predicted by least cost distance from the mouth of the river, tide, and gage height. We then examined the effect of temperature and salinity on residency of immature bull sharks in different regions of the river. Results of this study will significantly improve our understanding of how latitudinal variation in temperature and salinity influence immature bull shark residency, allowing us to better predict the effects of a changing climate on this species.


    4.    AES Carrier Award  Detection of Numerous Algal Toxins in Immature Bull sharks Carcharhinus leucas Collected from an Estuary of National Significance. Michelle Edwards*, Harbor Branch Oceanographic Institute, Florida Atlantic University; Adam Schaefer, Abt Associates; Malcolm McFarland, Harbor Branch Oceanographic Institute, Florida Atlantic University; Spencer Fire, Florida Institute of Technology; Christopher Perkins, Center for Environmental Sciences and Engineering, University of Connecticut; Matthew Ajemian, Harbor Branch Oceanographic Institute, Florida Atlantic University   edwardsm2019@fau.edu

    This study explored spatiotemporal patterns in baseline algal toxin concentrations in immature bull sharks (Carcharhinus leucas) of the Indian River Lagoon (IRL), an estuary of national significance that has been considerably impacted by multiple toxic harmful algal blooms. Because they are apex generalists that display residency in the IRL, immature bull sharks may serve as a useful bioindicator, acting as a proxy for contaminants in the environment and lower trophic species. Concentrations of algal toxins were assessed from samples collected from 50 immature bull sharks captured in the IRL between Brevard and Martin counties from 2018–2020. Ultra-performance liquid chromatography/tandem mass spectrometry was used to measure toxins in bull shark gut contents, plasma, and liver. Analysis of samples (n = 123) demonstrated the presence of multiple algal toxins (microcystins, nodularin, lyngbyatoxin, domoic acid, okadaic acid, and brevetoxin) in the tissues of bull sharks. This study was the first to measure multiple algal toxins in bull sharks of the IRL and one of the few to measure algal toxins in wild sharks.


    5.    AES Carrier Award  Standardizing non-lethal fin clip and biopsy sampling for trace element analysis in bull (Carcharhinus leucas) and tiger sharks (Galeocerdo cuvier). Julia Smith*, Australian Rivers Institute, School of Environment and Science, Griffith University; Erin Woodward, School of Environment and Science, Griffith University; Liesbeth Weijs, Australian Rivers Institute, School of Environment and Science, Griffith University; William Bennett, Coastal and Marine Research Centre, Cities Research Institute, School of Environment and Science, Griffith University   julia.smith@griffithuni.edu.au

    Trace elements in sharks are often measured in internal tissues, such as muscle and liver, from dead specimens. However, being able to analyze trace elements in tissue from living sharks can be beneficial, especially when it complements dietary and tracking data. Some non-lethal tissue samples, such as fin clips and biopsy punches, are already routinely collected during scientific field trips, but it is unknown whether these tissue samples adequately represent trace element concentrations in internal tissues. The objectives of this study were to determine: 1) if essential and nonessential trace elements differed among three first dorsal fin clip locations; 2) whether biopsy punch samples were representative of trace elements in other dermal denticle (scales/skin) samples; and 3) if fin clip and biopsy samples correlate to more commonly studied internal tissues, such as muscle and liver. Shark tissue samples from bull (Carcharhinus leucas) and tiger sharks (Galeocerdo cuvier) were collected opportunistically in collaboration with the Queensland Shark Control Program (QSCP) between 2019 and 2021 in South East Queensland, Australia. Samples were digested in acid using a microwave before being analyzed by inductively coupled plasma – mass spectrometry (ICP-MS) for 20 essential and non-essential trace elements including arsenic, chromium, cobalt, copper, iron, manganese, mercury, selenium, and strontium. The outcomes will assist in standardizing future sample collection protocols for trace element analysis in non-lethal tissues while also providing baseline concentrations to assess shark health and potential exposure to contaminants.


    6.    AES contributed  Effects of Increased Temperature on Growth and Development of Embryonic Whitespotted Bamboo Sharks, Chiloscyllium plagiosum. Madeleine Caraway*, University of Alabama at Birmingham; Kady Lyons, Georgia Aquarium; Jennifer Wyffels, University of Delaware; Andrew Gentry, UAB Biology Department   caraway@uab.edu

    To understand how future global ocean warming will affect embryos of oviparous elasmobranchs, this study tested how key characteristics of the growth and development in one species were altered by increased water temperatures. Wild populations of Chiloscyllium plagiosum are distributed across a large geographical range and, as such, live in a wide range of water temperatures. Species with preadaptation to greater variability in temperature may be more resilient to rapid warming; on the other hand, for a population adapted to a certain temperature within its locality, the rapid warming may have detrimental consequences. Specifically, it is predicted that the following occurs in C. plagiosumembryos incubated at higher temperatures compared to lower temperatures: faster rates of in ovo growth and yolk consumption, higher in ovo mortality rates, shorter durations of incubation, and higher proportions of embryos with visible physical deformities. Eggs were collected from the McWane Science Center’s aquarium and incubated in one of three tanks: control (26°C), intermediate (28°C), or warmest (30°C). Temperature increments above the control correspond with the predicted global ocean temperature increases over the next 50 and 100 years, respectively. While data collection remains ongoing, preliminary results indicate that, at higher incubation temperatures, growth and yolk consumption are faster, mortality rate is higher, and more physical deformities are observed. In conclusion, exposure to increased water temperatures appears to accelerate the growth of embryonic whitespotted bamboo sharks, and the impacts this has on their development are yet to be determined.


    7.    AES contributed  Use of Coelomic Fluid as a Noninvasive Indicator of Reproductive Status in Elasmobranchs. Emily Sapp*, University of North Florida; Jim Gelsleichter, University of North Florida   emilygsapp@gmail.com

    Information on reproduction in elasmobranchs is important for the management and conservation of populations. There has been progress in the field of elasmobranch reproduction; however, our ability to obtain reliable data without animal euthanasia is still extremely limited. Therefore, there has been a call for nonlethal approaches for identifying reproductive status, such as ultrasonography and blood analyses. Although useful, these techniques can be limited with respect to access to equipment and reliability of blood analyses. This study will investigate whether a new noninvasive approach, examination of coelomic fluid (CF), can provide a reliable indicator of reproductive status. CF is fluid that bathes the internal organs of the abdominal cavity, including ovaries, and can be sampled noninvasively through catheter. Recent studies on CF have demonstrated the presence of yolk platelets in the fluid, a specific indicator follicular development. This suggests that CF may provide a more detailed representation of reproductive state, than other nonlethal approaches, such as plasma hormone levels. Therefore, we examined CF collected from Atlantic Stingrays (Hypanus sabinus) which serve as a model elasmobranch for this work due to their well-described pattern of reproduction, abundance, and easily accessible coelomic pores. In this presentation, we report on preliminary findings regarding differences in gonadal steroid hormone concentrations and protein content in CF in relation to reproductive stage, as well as variations in gonadal steroid concentrations in CF and those in plasma.


    8.    AES contributed  Biotic and Abiotic Drivers of Polyandry in Sharks and Rays. Azsha Hudson*, Scripps Institution of Oceanography; Kady Lyons, Georgia Aquarium; Chris Mull, Dalhousie University; Gregory Rouse, Scripps Institution of Oceanography; Eric Archer, Southwest Fisheries Science Center (NMFS/NOAA); Dovi Kacev, Scripps Institution of Oceanography   azsha_h@yahoo.com

    Multiple paternity behavior in sharks has been recorded in seven elasmobranch orders and may be the plesiomorphic condition for the clade. Of the litters tested for genetic relations, 87% were found to have genetic contributions from two or more fathers. The rate of polyandry varies widely (0- 100%) amongst species studied. This study addresses potential biotic and abiotic drivers of multiple paternity while also investigating whether the rate of polyandry can be correlated with the conservation status as defined by the IUCN. The biological predictor variables that we consider include phylogeny, reproductive mode, known sperm storage, and effective population size. The environmental predictors include habitat type and oceanic region.


    9.    AES contributed  Seasonal movements of blacktip sharks, Carcharhinus limbatus, in the Northwest Atlantic. Jackson Bialek*, Florida Atlantic University; Beth Bowers, Florida Atlantic University; Ryan Stolee, Florida Atlantic University; Stephen Kajiura, Florida Atlantic University   jbialek2020@fau.edu

    Blacktip sharks (Carcharhinus limbatus) are an important upper trophic level predator, and represent a large commercial shark fishery in the United States. This species forms massive aggregations every winter off the Southeast Florida coast, and migrates northward for the summer. However, their migratory route and the northern terminus of their migration are unknown. To investigate the seasonality of blacktip movements, we captured 15 male sharks at the southern terminus of their migration between 2017-2021, and instrumented them with fin-mounted Smart Position and Temperature (SPOT) satellite tags. Geolocations were analyzed for seasonality, and water temperature profiles derived from tag sensors were examined to understand their thermal preferences. Sea surface temperatures (SST) were collected from remote sensing sources and used to visualize the concurrence of migratory movements with oceanic thermal conditions. We observed a distinct seasonal pattern to the locations of these sharks. Overwintering occurred off Southeast Florida in January-March, with individuals utilizing April and May as transitory months, wherein they moved northward to established mating grounds off Georgia and South Carolina. From June-September sharks ranged as far north as New York before beginning their southward migration. These sharks appeared to maintain a relatively narrow thermal profile throughout their migratory route, with 83% of detections within a temperature range of 21-25˚C. As global ocean temperatures increase in the future, it will be essential to understand these migratory patterns to better predict population-level shifts in behavior that will contribute to the effective management and conservation of this ecologically and commercially important species.


    10.    AES contributed  Effects of Climate Change on the Migration Phenology of Juvenile Blacktip Sharks (Carcharhinus limbatus). Victoria Goldner*, New College of Florida; Tonya Wiley, Havenworth Coastal Conservation; Jayne Gardiner, New College of Florida   victoria.goldner18@ncf.edu

    Seasonal temperature change has been shown to be a key driver of migration for many species. Increasing ocean temperatures have been observed to cause shifts in the range and timing of migratory movements in marine animals, including sharks. For harvested species, these behavioral changes could have significant implications for fisheries management. The blacktip shark (Carcharhinus limbatus) is one of the Gulf of Mexico’s most recreationally and commercially important species. Terra Ceia Bay, FL, is a nursery for blacktip sharks that has been extensively studied. In the late 1990s through early 2000s, young-of-the-year sharks were found to reside in the bay for the first 6 months of life, depart in October to November following water temperature drops of at least 1.5°C over two days, and return beginning in April. The goal of this study was to examine the current timing of immigration/emigration of blacktip sharks from this nursery. Departure and return dates of acoustically-tagged juvenile blacktip sharks (n=30, tagged from 2016-2021) to/from Terra Ceia Bay were determined using a directionally-gated array of acoustic receivers. Mixed-effects models were used to examine the effects of absolute water temperature, change in water temperature, and day length on the timing of immigration and emigration. Results indicated a shift during the last two decades towards both later departures and earlier returns from/to this nursery. This study furthers our understanding of the effects of climate change on migratory fishes and provides valuable information for adapting management of this species.


    11.    AES contributed  Predicting Elasmobranch Habitat Partitioning in a Florida Coastal River. Simon Bustetter*, New College of Florida; Tonya Wiley, Havenworth Coastal Conservation; Jayne Gardiner, New College of Florida   sbustetter@ncf.edu

    Estuaries provide vital nursery habitats for many marine species including sharks and rays; yet the habitat preferences of elasmobranchs within estuarine rivers are highly understudied. This study aims to determine which elasmobranch species are present in the Manatee River (FL) and predict habitat use and partitioning within the tidally influenced system, which flows into Tampa Bay. Catch rates and environmental factors from the 2018 - 2021 NOAA Gulf of Mexico Shark Pupping and Nursery gillnet and longline survey were analyzed. Within the river, 11 species of elasmobranchs were caught, eight of which were primarily caught near the mouth of the river in higher salinities. Only Bull Shark (Carcharhinus leucas), Atlantic Stingray (Hypanus sabinus), and Cownose Ray (Rhinoptera bonasus) were found further upriver in lower salinities. Boosted Regression Tree analyses were conducted to determine the major environmental factors impacting species presence. General Linear Models were used to examine habitat associations by size for the principal species– Atlantic Sharpnose Shark (Rhizoprionodon terraenovae), Blacktip Shark (Carcharhinus limbatus), Bull Shark, Cownose Ray, and Bonnethead Shark (Sphyrna tiburo). Despite the small study area (28.6 km2), habitat partitioning among all species was observed. Depth, dissolved oxygen, and salinity were the most influential environmental factors for partitioning among a majority of species in the river, while within the principal species, turbidity and depth most influenced partitioning by body length. This research highlights the need to determine habitat preferences in order to better understand elasmobranch occurrence and movements within river systems.


    13.    AES contributed  Community interviews from Andros Island, The Bahamas reveals new insights on the distribution and use of Critically Endangered Smalltooth Sawfish. Khrysdovãn Caroll*, Bahamas Agriculture and Marine Science Institute; Tristan Guttridge, Saving the Blue; Annie Guttridge, Saving the Blue; Philip Matich, Saving the Blue   concheror.inc@gmail.com

    The Bahamas is among the last remaining refuges for the Critically Endangered Smalltooth Sawfish, Pristis pectinata, and the 'beacon of hope' population on Andros Island may be critical to their recovery. While legislation in the Bahamas prohibits export or import of shark products, no such protection exists for batoids including sawfish. Among the most important conservation actions, community stewardship is a top priority in the region, as well as identifying and protecting critical habitats. As such, targeted efforts to protect essential habitats coupled with community-led conservation actions provides a path forward for sawfish recovery. Here we present the results of structured interviews (n = 78) with community members that frequent Andros’ waters to 1) describe temporal and spatial patterns in sawfish distribution in Andros, and 2) identify key regions or habitats deserving sawfish-specific monitoring and future protection. Findings revealed encounters with sawfish of all life stages, which were distributed across the entire island, with comparable numbers of animals recorded along both coastlines. Encounters were predominantly in shallow (< 2m), muddy flats, close to shore (< 1km). Most notable was the first documentation of young-of-the-year smalltooth sawfish on the east coast, as well as clustered sightings in the back country of southern Andros, indicative of potential critical nursery habitats for the species. These and other findings are discussed along with recommendations for local conservation initiatives and enhanced community stewardship.


    14.    AES contributed  A first assessment of the distribution and abundance of pelagic species at Cocos Ridge seamounts using drifting baited remote cameras. Marta Cambra*, Universidad de Costa Rica; Frida Lara-Lizardi, MigraMar; César Peñaherrera-Palma, MigraMar; Alex Hearn, Galapagos Science Center; James T. Ketchum, Pelagios Kakunjá; Patricia Zarate, Instituto de Fomento Pesquero; Carlos Chacón, Fundación Pacífico; Jenifer Suárez-Moncada, Dirección del Parque Nacional Galápagos; Esteban Herrera, Área de Conservación Marina Cocos; Mario Espinoza, Universidad de Costa Rica   m.cambra.agusti@gmail.com

    Understanding the link between seamounts and large pelagic species (LPS) may provide important insights for the conservation of these species in open water ecosystems. The seamounts along the Cocos Ridge in the Eastern Tropical Pacific (ETP) ocean are thought to be ecologically important aggregation sites for LPS when moving between Cocos Island (Costa Rica) and Galapagos Islands (Ecuador). However, to date, research efforts to quantify the abundance and distribution patterns of LPS beyond the borders of these two oceanic Marine Protected Areas (MPAs) have been limited. This study used drifting-pelagic baited remote underwater video stations (BRUVS) to investigate the distribution and relative abundance of LPS at Cocos Ridge seamounts. A total of 21 species were recorded including elasmobranchs, small and large teleosts, dolphins and one sea turtle. Depth of seamount summit was the most significant driver for LPS richness and abundance which were significantly higher at shallow seamounts (< 400 m) compared to deeper ones (> 400m). Distance to nearest MPA was also a significant predictor for LPS abundance, which increased at increasing distances from the nearest MPA. Our results suggest that the Cocos Ridge seamounts, specifically Paramount and West Cocos which had the highest LPS richness and abundance, are important aggregation sites for LPS in the ETP. Further research is still needed to demonstrate a positive association between LPS and Cocos Ridge seamounts. Our findings showed that drifting pelagic BRUVS are an effective tool to survey LPS in fully pelagic ecosystems of the ETP.


    15.    AES contributed  Prey Availability and Tide Influence on the Movement of Juvenile White Sharks (Carcharodon carcharias) in the Minas Basin. Javon Lo*, Dalhousie; Charles Bangley, Dalhousie; Fred Whoriskey, Dalhousie; Rod Bradford, Fisheries and Oceans Canada; Greg Skomal, Massachusetts Division of Marine Fisheries; Megan Winton, Atlantic White Shark Conservancy; Bryan Franks, Jacksonville University; Chris Fischer, OCEARCH   javonlo8@gmail.com

    The Minas Basin is under development as an area for the installation of tidal turbines and is also the site of several local fisheries. To understand the potential risks to juvenile white sharks, Carcharodon carcharias, in and around the Minas Basin, we analyzed data on the movements of acoustically tagged sharks in the area. The study also examined the potential influences of prey species, striped bass (Morone saxatilis), co-occurrence with the sharks and tide height on movements. The area was divided into three distinct regions: the main basin, the mouth of the Avon River, and the passage to the Bay of Fundy. Between 2017-2020, 10 sharks and 136 striped bass tagged by the Massachusetts Marine Fisheries Shark Research Program, OCEARCH, and Fisheries and Oceans Canada were detected in the study area. Based on size estimates, all sharks were found not yet mature and were at the ontogenetic stage in which fish are the main prey item. Detections of most individuals occurred at acoustic receiver stations within the Minas Passage, but the highest mean residence times for individual animals occurred at stations found outside of the passage within the Minas Basin. The relationship between white shark presence, tide height, and striped bass abundance will be determined using a mixed behavioural model. The results from this project will contribute information on the impacts of human activity on this at-risk species.


    16.    AES contributed  Correlating juvenile white shark eDNA sampling to acoustic telemetry monitoring at a Southern California aggregation site. Zach Merson*, California State University, Long Beach; Emily Spurgeon, California State University, Long Beach; James Anderson, California State University, Long Beach; Brian Stirling, California State University, Long Beach; Patrick Rex, California State University, Long Beach; Elizabeth Jahn, California State University, Long Beach; Sergio Madrigal Mora, California State University, Long Beach; Javier Mata, California State University, Long Beach; Haylee Kramar, California State University, Long Beach; Matthew Barnes, Texas Tech University; Chris Lowe, California State University, Long Beach   zach.merson01@student.csulb.edu

    Metagenomics, the study of genetic material in the environment, is an emerging method used to answer ecological questions in marine systems. While environmental DNA (eDNA) is an adept approach for assessing species presence, additional calibration is needed to reliably generate abundance estimates, especially for rare, large elasmobranchs. Juvenile white sharks (Carcharodon carcharias) in the Southern California Bight form distinct aggregations, and typically remain from spring to late fall. We present a comparison between eDNA quantity and acoustic telemetry at the largest juvenile white shark aggregation in Southern California. eDNA samples were collected at Padaro Beach, Carpinteria, CA in May 2020, July 2020, and October 2021. Water samples were filtered, then processed using quantitative PCR. A Vemco Positioning System acoustic receiver array is deployed at Padaro Beach to detect tagged white sharks. We tracked shark positions before and during eDNA sample collection to determine how shark count and location influences metagenomic detection at the site. Heatmaps interpolated from DNA collection sites and acoustic receiver locations show the centroid of eDNA detections is offset from the centroid of acoustic detections, potentially due to currents. Fine-scale positions of individual sharks show their movement across the site and proximity to eDNA sampling locations. Preliminary results suggest that eDNA may correlate with abundance for large elasmobranchs that occur in low densities. Our future directions are to expand eDNA sampling to additional sites, and to monitor environmental conditions and conduct aerial surveys at the same time as eDNA collection.


    17.    AES contributed  Swimming Kinematics of Shoaling Leopard Sharks (Triakis semifasciata). Charles Romero*, Florida Atlantic University; Lenia Jordan, Florida Atlantic University; Andrew Nosal, University of San Diego; Marianne Porter, Florida Atlantic University   cromero2017@fau.edu

    Previous work has identified shark swimming patterns showing an offset mode of wave propagation between the anterior (head) and posterior (tail). Specifically, the head yaw amplitude and frequency are decoupled from the tailbeat where frequency is greater anteriorly and amplitude is greater posteriorly. Previous studies have quantified these variables in obligate ram ventilators (bonnethead, hammerhead, blacktip), but have not evaluated buccal ventilating species. Due to their ability to rest on the seafloor, buccal pumping sharks may swim with a less pronounced head yaw amplitude and frequency than ram ventilators. Here, we quantified straight swimming kinematics of shoaling leopard sharks (Triakis semifasciata). We hypothesized that leopard shark head yaw amplitude and frequency will be reduced compared to ram ventilators quantified in previous papers. Also, we hypothesize that leopard sharks employ an offset mode of wave propagation resulting in different strouhal values than obligate ram ventilators, suggesting they swim less efficiently. We obtained aerial video filmed in La Jolla, CA and used Logger Pro 3.16 software to motion track individuals using 5 midline anatomical landmarks. We quantified parameters according to body length including velocity, anterior/posterior amplitude/frequency, and strouhal number. Contrary to our initial hypothesis, preliminary data suggests that leopard sharks employ an offset wave, similar to other sharks.


    18.    AES contributed  Turning Maneuvers of Volitional Swimming Leopard Sharks. Lenia Jordan*, Florida Atlantic University; Dante Romero, Florida Atlantic University; Andrew Nosal, U. of San Diego; Marianne Porter, Florida Atlantic University   mporte26@fau.edu

    In previous studies, shark maneuvering has been observed in constrained tanks or elicited by sensory stimuli to encourage tight abrupt turns. Morphological and kinematic studies on leopard sharks (Triakis semifasciata) found that the vertebral column plays a dominant role in passive body mechanics that impact body curvature during maneuvering. However, body shape (total length, width at the pectoral fines, and fineness ratio) were variables that influenced turning. In this study, we quantified turning maneuvers and body shape in shoaling leopard sharks. Turning was defined as the head and caudal fin being closer together during maximum flexion, and this variable was quantified using a bending coefficient. Body shape was quantified using animal total length, width at the pectoral fins, and a fineness ratio that calculated a 2D shape. We hypothesized that leopard sharks with longer and slimmer body shapes (low fineness ratio) would have tighter turns, than sharks with stocky (larger fineness ratio) bodies. Videos were obtained using aerial drones from the nearshore environments in La Jolla, CA, an area known to have a high abundance of leopard sharks. We used Logger Pro 3.16 software to point track individuals using five points along the body midline in each frame of video. Understanding maneuvering kinematics is useful for understanding animal interactions such as foraging and mating.


    19.    AES contributed  Getting to Nose You: Understanding Chondrichthyan Nasal Morphology through CAD models. Lauren Simonitis*, University of Washington’s Friday Harbor Labs; Adam Summers, University of Washington’s Friday Harbor Labs   lauren.simonitis@gmail.com

    Cartilaginous fishes have a wide array of olfactory morphologies affecting both the flow and sensitivity inside the olfactory organ. For instance, in sphyrnid sharks, different areas of the tubular olfactory organ experience different water velocities: the highest velocities are found in the center of the organ with decreased water velocities at either end. Similarly, the central olfactory lamellae have a higher surface area devoted to sensory area than the lamellae at either end of the organ. This raises an interesting possibility - perhaps the location/density of sensory epithelium is related to water velocity, which sets the range of sensitivity of a particular region of the rosette. A somatotopic mapping of the sensory epithelium could then transduce a wide range of stimulant dilutions. The mechanisms of flow are known from a computational model of the Small Eyed Hammerhead Shark (Sphyrna tudes). The more than 900 species of cartilaginous fishes gives us a fertile field to apply similar computational models, or less computer intensive physical models, to understand variation in flow. Here we use contrast-enhanced computed tomography (CT), scanning electron microscopy (SEM), and histology to build computer-aided design (CAD) models of cartilaginous fish noses. Our goal is to assess the diversity in morphology across Chondrichthyes, quantify relationships between olfactory morphology and sensory input, and model the hydrodynamics inside the olfactory organ. We hypothesize that we will see similar trends to what we see in sphyrnids- olfactory lamellae experiencing higher water velocities will have more surface area dedicated to sensory structures.


    21.    AES contributed  Functional implications reflected in neurocranial morphology of lamniform sharks (Elasmobranchii: Lamniformes). Jake Wood*, DePaul University; Kenshu Shimada, DePaul University   chondrichthyic@gmail.com

    Lamniform sharks (Elasmobranchii: Lamniformes) display diverse habitat preferences and lifestyles. Based on museum specimens and published illustrations, we examined the proportion of the anteroposterior length of the rostral, olfactory, optic, and otic regions with respect to the neurocranial length in each lamniform species as a proxy of relative importance of each sensory region (electroreception, olfaction, vision, and 'coordination') to its lifestyle. We show that: 1) Carchariasand Odontaspis(sandtiger sharks) have short rostral and large olfactory regions indicative of demersal lifestyles with elevated olfaction for locating prey; 2) Alopias pelagicus, A. vulpinus,andLamna(pelagic and common threshers and porbeagle and salmon sharks) have moderately long rostral and large optic-otic regions suggestive of fast-swimming pelagic lifestyles with enhanced vision and coordination for rapid prey hunting aided by electroreception; 3) MegachasmaandCetorhinus(megamouth and basking sharks) have a short rostral and large olfactory-otic regions indicative of elevated olfaction for planktivory and coordination for migratory behaviors; and 4) CarcharodonandIsurus(white and mako sharks) have relatively long rostral and optic regions for a moderate reliance of electroreception and enhanced vision for capturing large prey. Pseudocarchariasand A. superciliosus(crocodile shark and bigeye thresher) living in deeper waters have large optic regions, but the trend is not universal; most strikingly, Mitsukurina(goblin shark) has an exceptionally elongated rostrum with the smallest optic region among all the lamniforms likely reflecting its heavy reliance on electroreception relative to vision. Our study provides new insights into their evolutionary history and implications for conservation biology.


    22.    AES contributed  Chomping at the bit: the effects of wear on shark tooth puncture performance and morphology. Ryan Sesler, Allegheny College; Lisa Whitenack*, Allegheny College   lwhitena@allegheny.edu

    Sharks replace their teeth regularly, producing thousands of teeth in their lifetime. However, previous work has shown that shark teeth are structurally strong, suggesting the frequent replacement of teeth is not likely due to tooth breakage. Instead, the frequency of replacement may be due to tooth wear. As the tooth tip and edges wear, the surface area of these features increases, which should lead to less stress produced by the tooth during a bite and more force required to puncture the prey item. Our aim is to analyze the impact that wear holds on puncture performance and tooth morphology. For our preliminary experiment, serrated teeth from three species were utilized: Carcharhinus plumbeus, C. leucas, and C. limbatus. We found that over 400 punctures, tooth wear occurs, and force to puncture increases. The radius of curvature of the tooth apex increases by 5.8 to 9.9 microns, while the serrations decrease in height by 0.1 to 0.8 microns, and the radius of curvature increases by 0.1 to 2.0 microns. As the tooth wears, forces increase by 10.6 to 19.1 N, depending on the species. In a dramatic example, one C. plumbeus tooth tip broke midway through the trials. The tooth apex radius of curvature went from 6.3 microns to 47.9 microns, while the puncture force increased from 6.2 to 47.9 N. While all of these forces are below the bite forces of the species measured to date, these preliminary results suggest that even small amounts of wear may affect tooth performance.


    23.    AES contributed  Histological Comparison of Shark Dermis Across Various Ecomorphologies. Olivia Schuitema*, University of North Florida; Dr. Maria Laura Habegger, University of North Florida   olivia.schuitema@unf.edu

    The integument plays an essential role in the structural support, protection, and hydrodynamic capability among fishes. Within sharks, most of our knowledge centers on the superficial epidermal layer containing the dermal denticles. However, the deepest and most prevalent layer, the dermis, is the least understood. The dermis layer in sharks is composed of two sublayers, the stratum laxum and the stratum compactum, both housing supportive collagen and elastin fibers. There may be morphological and compositional differences in the dermis layers across different species of sharks, although the extent of such is unknown. These potential differences in dermis layer thickness and fiber density may be characteristic among different sharks swimming modes and swimming ecologies. The goal of this study is to thoroughly characterize and describe the dermis of four shark species representing various ecomorphologies including Ginglymostoma cirratum, Carcharhinus limbatus, Sphyrna mokarran and, Isurus oxyrinchus. To measure dermal layer thickness and fiber density, sixteen locations along the body of each shark were sampled and stained using histological methods, targeting collagen and elastin fibers. Preliminary results showed thicker collagen bundles in the caudal location of I. oxyrinchus, and a higher density of elastin fibers in the pectoral fin location in S. mokarran. Additionally, the dermal layer was thinner in the flank region of all study species. The results of this research will contribute novel information on dermal morphology among sharks with different ecomorphologies, and perhaps expand our understanding on how these differences may relate to the variety of swimming modes represented among them.


    25.    Contributed ASIH Ichthyology  Let’s get moving: a study of toughness and stiffness of the shortfin mako, Isurus oxyrinchus vertebrae. Maria Uribe Mejia*, Florida Atlantic University; Delaney Frazier, Florida Atlantic University; Aubrey Clark, Florida Atlantic University; Dr. Marianne Porter, Florida Atlantic University   muribemejia2021@fau.edu

    The cartilaginous vertebral columns in elasmobranchs (sharks, skates, and rays) experience compression and tension while swimming. Previous studies tested three ontogenetic groups and divided the body into two regions (anterior and posterior) for six Carcharhiniformes and Lamniformes species. They found that the young of the year group outperformed the other mature ontogenic groups in stiffness and strength, specifically in the posterior region. They hypothesized that the posterior region of axially undulating sharks needed to be stiffer and stronger to support the forces required for fast, constant swimming. We tested three regions of Isurus oxyrinchus, shortfin mako, (anterior, middle, and posterior) for toughness and stiffness using relevant biological strain rates of 0.1%, 1.0%, and 10%. We sampled three consecutive vertebrae from each of the regions from eightI. oxyrinchus, totaling in nine vertebrae per animal. We hypothesized there will be a variation in toughness and stiffness between regions, with the posterior region being the most significant due to the higher forces required for fast swimming in Lamniformes sharks. We found that there was a significant difference in toughness among the regions; the posterior having the highest toughness. However, there was no significant difference in stiffness among the regions. The consistent stiffness values in shortfin mako suggest that vertebral columns in this species may require uniform stiffness to generate fast swimming.


    26.    Contributed ASIH Ichthyology  Regional comparison of vertebrae stiffness and toughness across elasmobranch species. Delaney Frazier*, Florida Atlantic University; Maria Uribe Mejia, Florida Atlantic University; Aubrey Clark, Florida Atlantic University; Dr. Marianne Porter, Florida Atlantic University   dfrazier2017@fau.edu

    The cartilaginous vertebrae of elasmobranchs are highly mineralized, and the mineral amount and architecture vary among species. During swimming, the vertebrae experience compressive and tensile forces with every caudal fin lateral undulation. A previous study separated the body into an anterior and posterior region, and individual vertebrae were tested in compression. They found that stiffness and toughness were greater in the posterior region across six species. Increased mechanical properties in the posterior region are thought to be associated with the larger thrust forces needed for swimming. To investigate this relationship further, we quantified vertebral mechanical properties from 12 species and divided the column into three regions (anterior, middle, and posterior). We tested vertebrae in compression and calculated stiffness (resistance to compression and deformation) and toughness (ability to absorb energy) at three biologically relevant strain rates (0.1%, 1.0%, and 10%). Species and region were both significant effects in statistical models evaluating toughness and stiffness. Across species, toughness is greatest in both the anterior and posterior regions and least in the middle. Carcharhiniformes have the greatest toughness, Orectolobiformes were intermediate, and Lamniformes were the least. Stiffness is greatest in the middle region and greatest in Orectolobiformes, intermediate in Carcharhiniformes, and least in the Lamniformes. These data allow us to evaluate the mechanical properties of cartilaginous vertebral columns among species and along the column to better understand the diversity of swimming wavelengths found in elasmobranch fishes.


    27.    Contributed ASIH Ichthyology  Parental Analysis of Brood for the Mouthbrooding Marine Catfish, Ariopsis felis. Katherine Lanoue*, Texas A&M University- Corpus Christi; Charles Cotton, State University of New York Cobleskill; Dean Grubbs, Florida State University; Elizabeth Hunt, Texas A&M University- Corpus Christi; David Portnoy, Texas A&M University- Corpus Christi   katherine.lanoue@tamucc.edu

    The hardhead catfish (Ariopsis felis) is a marine species commonly observed in Atlantic coastal waters along the southeastern United States and in the Gulf of Mexico. Though these fish are abundant, there is currently little knowledge about mating behavior in the species. During reproduction, fertilized eggs are picked up by male catfish and carried in the mouth, where the young develop for up to three months. This type of reproductive strategy, mouth brooding, could lend itself to polygyny and/or alternative mating strategies, such as brood parasitism. While these topics have been previously explored in other fish species, they have yet to be addressed in marine catfish. To investigate this, several male Ariopsis felis and their respective broods were collected from the northern Gulf of Mexico and genotyped using double digest restriction site-associated DNA (ddRAD) sequencing. The data was then used for assessment of kinship among the brood as well as parentage between the male and his putative offspring. The results of this study are intended to shed more light on the biology of the marine catfish and potentially add additional insight to alternative mating strategies in mouthbrooding species.


    28.    Contributed ASIH Ichthyology  Age-based Demography and Reproductive Biology of areolate grouper Epinephelus areolatus, southern Japan. Kosuke Oyama*, Kagoshima University; Kenshiro Hikichi, Kagoshima University; Emma Moritoshi, Kagoshima University; Gen Kume, Kagoshima University   dhuangjiang@gmail.com

    The demographic analysis of areolate grouper Epinephelus areolatus, one of the most important groupers in commercial and ecological perspectives in Kagoshima Bay, southern Japan, was conducted in this study. Specimens were obtained from 2018 to 2021 through mainly hook-and-line, supplementally market purchase and scuba diving. For aging analysis, sagittal otoliths were removed and processed into transverse sections (n = 130). Gonads were removed, measured for wet weight, and processed into sectioned for histological analysis (n = 213). All otoliths were readable. The observation of the transverse sections of otoliths showed a validity that opaque zones could be regarded as annuli. A von Bertalanffy growth function was fitted to total length (TL) at the assumed age to estimate the growth characteristics. The asymptotic TL, the growth coefficient, and the theoretical age at TL = 0 were estimated to be 468.3 mm, 0.289, and -0.837, respectively. The maximum age was 19 years. Males were obviously larger and older than females. The maximum size for males and females were 494 mm and 470 mm, respectively. For females, the age and size at 50% sexual maturity were estimated to be 3.0 years and 304 mm, respectively. The spawning season was estimated to be between July and October. The histological observation for gonadal development strongly suggested that all individuals have bisexual gonads before sexual differentiation to females. The present results indicated a potential that primary male could exist in the population and suggested that E. areolatus would be a diandric protogynous hermaphrodite.


    29.    Contributed ASIH Ichthyology  The larval attachment organ of the Bowfin Amia calva (Amiiformes: Amiidae). Amanda K. Pinion, Department of Ecology and Conservation Biology, Texas A&M University; Kole M. Kubicek, Department of Ecology and Conservation Biology, Texas A&M University; Ralf Britz, Senckenberg Naturhistorische Sammlungen Dresden, Museum für Zoologie; Dustin S. Siegel, Department of Biology, Southeast Missouri State University; Kevin W. Conway*, Department of Ecology and Conservation Biology, Texas A&M University   conwaykw@gmail.com

    Larval attachment organs (LAOs) are unicellular or multicellular organs that enable the larvae of many actinopterygian fishes to adhere to a substrate before yolk-sac absorption and the free-swimming stage. In this study, we document the LAO of the Bowfin, Amia calva, using a combination of scanning electron microscopy and light microscopy. We show that the LAO of A. calva represents a super-organ surrounded by a wall and containing at its center many smaller multicellular organ units, each comprised of attachment and support cells. Attachment cells are secretory and house large vacuoles filled with what appears to be a glycoprotein. We compare the LAO of the Bowfin to that present in members of the Lepisosteidae (gars) and discuss putative shared and derived characters of the LAO in both groups that may represent synapomorphies in support of the Holostei.


    30.    ASIH Storer Ichthyology  The functional morphospace of locomotor morphology of Neotropical poecilids. PATRICIA TORRES-PINEDA*, EEB University of Michigan   ptorresp@umich.edu

    Morphological traits affecting the capacity to perform ecologically relevant functions are likely adaptively relevant (Arnold 1983), thus phenotypic differentiation serve as a basis for predictions of the relationship between morphology and ecology. Phenotypic variability linked to locomotor performance in fishes, such as body and fin size and shape has been linked to habitat use as well as access to food and mates. Poeciliids (Cyprinodontiformes: Poeciliinae) a major component of Neotropical fish diversity, exhibit large variability in fin as well as body size and shape. Some of the variability observed is linked to sexual selection and phenotypic plasticity, however, analyses of functionally informed morphological traits at a macroevolutionary scale can help detect signals of adaptation. I measured and compared 16 functional morphological traits across main groups of the phylogeny of Poeciliinae. The morphospace of poecilids is extensive, with certain groups exploring novel spaces of the morphospace. The functional locomotor morphology constitutes an important dimension of phenotypic evolution in poecilids. Patterns recovered here will inform subsequent inferences and testing of the link of these traits with ecological divergence.


    31.    ASIH Storer Ichthyology  The Impact of Temperature Induced Vertebral Anomalies on C-start Swimming Performance in Astyanax mexicanus(Teleostei: Characidae). Kaleigh Arnold*, DePaul University; Windsor Aguirre, DePaul University   kaleigh.arnold902@gmail.com

    Fish throughout the world are facing threats from climate change, which can result in various types of developmental, ecological, and evolutionary consequences due to changes in temperature and habitat. To understand the implications that altered environments may have on fish populations, researchers have started to study the anatomical, physiological, and ecological responses of fish to changing temperatures in both field and laboratory settings. Alterations in gene expression and cell signaling are triggered from changes in developmental temperature; bone and skeletal development is at risk for malformations and abnormalities. However, there is relatively little known about how the presence of different skeletal anomalies impact specific kinematic characteristics such as swimming performance in fishes. To understand how these anomalies may affect fitness, measurements of C-start escape responses will be conducted in a lab strain of the Mexican tetra Astyanax mexicanus, as well as radiographic examinations of vertebral columns and specific anomalies that commonly develop in order to connect specific anomalies with changes in different components of the C-start response. We predict that the presence and severity of skeletal anomalies will be associated with poorer fitness levels as inferred from the C-start reaction. We also predict that anomalies in the caudal region of the vertebral column will have a greater impact on swimming performance than those in the precaudal region. This research will contribute to the ongoing efforts to understand how human alterations of the environment like climate change induced changes in water temperature impact the ability of organisms to perform in nature.


    34.    ASIH Storer Ichthyology  The Evolutionary History of Extant and Fossil Surgeonfishes and Relatives (Acanthuriformes). Aintzane Santaquiteria*, Department of Biology, The University of Oklahoma; Dahiana Arcila, Department of Ichthyology, Sam Noble Oklahoma Museum ofNatural History; Mark W. Westneat, Department of Organismal Biology and Anatomy, University of Chicago; Giorgio Carnevale, Dipartimento di Scienze della Terra, Università degli Studi di Torino; James C. Tyler, Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution; Ricardo Betancur-R., Department of Biology, The University of Oklahoma   aintzanesantaquiteria@gmail.com

    Acanthuriforms are a charismatic group of marine fishes that today include the popular surgeonfishes (Acanthuridae; 85 spp.) and the monotypic families Luvaridae (Louvar, Luvarus imperialis) and Zanclidae (Moorish idol; Zanclus cornutus). A close relationship between these three families is strongly supported by both morphological and molecular evidence. Acanthuriformes include one of the most complete fossil records among teleost fishes, providing an opportunity to integrate paleontological and neontological information in a total-evidence phylogenetic framework. Here, we inferred the most comprehensive time-calibrated phylogeny for this group integrating genomic and morphological data from both extant and fossil taxa. The molecular dataset generated includes a total of 1,046 markers sequenced from 82 extant species (~94% of the clade’s diversity). Of these, 56 species were newly sequenced using exon capture approaches (1,017 exons); sequences from 26 additional species from previous studies that examined 15 mitochondrial and nuclear legacy markers were also incorporated. The new morphological dataset comprises 107 skeletal characters coded from 25 extant and 33 fossil taxa. Using these two datasets, we conducted total-evidence analyses based on multiple subsets consisting of non-overlapping gene sets to simultaneously estimate the phylogenetic placement of fossils and the timing of lineage divergence. We also collected geometric morphometric data from fossils and extant species. With this robust phylogenomic framework, we will revisit a previous hypothesis suggesting that the planktivory lifestyle has independently evolved at least four times in Acanthuridae and that pelagic-feeding lineages have not yet reached the adaptive peak associated with planktivory.


    35.    ASIH Storer Ichthyology  Addressing the Evolutionary Relationships of the Deep Sea Fishes of the Order Trachichthyiformes. Fernando Melendez-Vazquez*, University of Oklahoma; Ricardo Betancur-R, University of Oklahoma; Dahiana Arcila, Sam Noble Oklahoma Museum of Natural History   fernando.melendez1@ou.edu

    Unraveling the evolutionary history of diversification across major deep-sea fish lineages by combining genomic and morphological data can provide new insights into phenotypic convergence and the origin of novel adaptations to this extreme environment. According to recent molecular studies, the order Trachichthyiformes comprises 68 species in five families, which include the Diretmidae, Anomalopidae, Trachichthyidae, Monocentridae, and Anoplogastridae. Early molecular and morphological studies have provided support for conflicting topologies among the major families of this group, including the non-monophyly of the family Trachichthyidae and long-standing controversies about their sister group relationships with Beryciformes and Holocentriformes. Here, we use genomic-wide exonic data sets (1,105 loci) and a variety of morphological traits previously proposed in the literature to tackle the phylogenetic relationships of Trachichthyiformes and to re-assess its sister group relationships. Our taxonomic sampling consisted of a total of 99 species, including 40 species in Trachichthyiformes, 44 in Beryciformes, and 15 species in Holocentriformes. Our preliminary results based on genomic data alone indicate a sister relationship between Beryciformes and Holocentriformes and a closer relationship with the percomorphs than with the Trachichthyiformes, but additional taxa are still to be added. Additional analyses will implement of variety of statistical methods (e.g., Gene Genealogy Interrogation) and will also integrate morphological traits in both separate and total evidence approaches. These results will provide valuable information for downstream studies addressing the evolution of bioluminescence, morphological adaptations, and colonization to deep-sea habitats, among others.


    36.    ASIH Storer Ichthyology  Orientation of Blacktip Sharks to Underwater Sound in the Acoustic Far-Field. Caroline Sullivan*, Florida Atlantic University; Edmund Gerstein, Florida Atlantic University; Stephen Kajiura, Florida Atlantic University   csullivan2014@fau.edu

    Sharks have been documented to show attraction to low frequency, pulsed sounds and have reportedly oriented to sound pressure in the acoustic far-field. In contrast, other work states that sharks lack the capacity to detect sound pressure and should respond only to particle displacement in the acoustic near-field. This study quantified the distance from which free-ranging sharks oriented to sound stimuli, to determine if sharks responded from beyond the acoustic near-field. Using an aerial drone, blacktip sharks (Carcharhinus limbatus) were filmed responding to a low frequency pulsed sound stimulus of 100-200 Hz, 200-400 Hz, or 400-800 Hz. The near-fields of the stimuli extended up to 30 meters for 100-200 Hz, 15 m for 200-400 Hz, and 7.5 m for 400-800Hz. Upon sound detection, C. limbatus elicited a dramatic 20-160 degree turn away from the speaker, and an increase in swimming velocity. Sharks responded to all frequencies from a distance of at least 62m. This indicates that sharks can detect and orient away from a sound stimulus at distances that extend well beyond the acoustic near-field, which suggests that they are using hearing and not lateral line stimulation. The hearing abilities of C. limbatus have not yet been investigated, however congeners have been reported to possess a greater density of sensory hair cells compared to other elasmobranchs, which is hypothesized to confer greater hearing sensitivity. The ability of C. limbatus to orient in the far-field provides evidence that sharks may have a hearing ability more specialized than previously thought.


    37.    ASIH Storer Ichthyology  The Cryptic Taxonomy of Cryptobenthic Reef Fishes in the Eviota sigillata Complex. Marta Gomez-Buckley*, University of Washington; Luke Tornabene, University of Washington   lapita@uw.edu

    With 123 species described to date, the genus Eviota (Gobiidae) is the most specious among the coral reef fishes. Most species of Eviota are small (<2 cm), and together with other cryptobenthic reef fishes, are one of the largest contributors of consumed biomass within coral reef ecosystems. Recent phylogenetic analysis of the Eviotagenus revealed multitude of species complexes, including cases in which only one nominal species contains multiple genetically distinct groups, with very subtle or non-existent differences in morphology or pigmentation (cryptic species). For this study, we concentrated on the E. sigillata complex. Currently two species, E. sigillata, and E. shimadai, have been described within this complex but drawing from available molecular analysis (based on COI sequences), it is projected that at least ten more species could be present. We examined over 100 specimens collected through the entire Indo-west Pacific, and from paratypes from museum collections. We recorded extensive morphological and meristic data, as well as live coloration patterns (~40% of all specimens available), in addition to the molecular analysis. Wide genome RADseq analysis is expected to shed light on how many species theE. sigillatacomplex contains.


    38.    ASIH Storer Ichthyology  Identification of larval Pacific Sand Lance (Ammodytes personatus) and Arctic Sand Lance (Ammodytes hexapterus) using COI and morphological characteristics. Laurel Nave-Powers*, University of Washington; Luke Tornabene, University of Washington   navepowl@uw.edu

    The Pacific Sand Lance (Ammodytes personatus) and Arctic Sand Lance (Ammodytes hexapterus) are ecologically important forage fishes in the Pacific Northwest of the United States. The recent taxonomic revision of Orr et al. 2015 has resulted in knowledge gaps due to the lack of diagnostic characters for the identification of the larvae of these two species in their area of overlap in the Bering Sea. The objectives of this research focus on the identification of larval Pacific Sand Lance and Arctic Sand Lance. We hypothesize that the presence and amount of pigment will be the primary diagnostic character separating the larvae, which will be supported by identifications using molecular data. Larvae of both species were identified using fixed nucleotide differences in the mtDNA genome at the COI gene. Specimens of each species were examined to identify morphological characteristics to diagnose them visually. The results show the primary diagnostic character separating the larvae is pigment, both dorsally and in number of melanophores post-anus. Overall, larval Arctic Sand Lance have more pigment than Pacific Sand Lance, and the pigment appears earlier in development. These characters will be tested on a second sample of larvae from both species. With these visual diagnostic characters, we can understand more about their interactions and distributions, which is currently only based on adults. The ability to identify the larvae of these two species morphologically will allow for more research to be done, in particular how they are interacting in their area of overlap in the Bering Sea.


    39.    ASIH Storer Ichthyology  Growth, Maturation, and Primary Male Development of Protogynous Pseudanthias rubrizonatus in Kagoshima Bay, Japan. Emma Moritoshi*, Kagoshima University; Haruka Matsumoto, Kagoshima University; Midori Matsuoka, Kagoshima University; Tomoki Sunobe, Tokyo University of Marine Science and Technology; Shinichi Dewa, Diving service Umiannai; Gen Kume, Kagoshima University   emmahinako@gmail.com

    Pseudanthias rubrizonatus is considered polygyny and monandric protogyny. However, in Kagoshima Bay, Japan, there are groups with over 10,000 individuals. The effect of larger groups size on the reproductive ecology of P. rubrizonatus was studied using histological observations of the gonads and growth analysis of otolith increments from undifferentiated juveniles to sexual differentiation, sex change, and maturation. By monthly sampling from July 2019 to March 2022, 519 P. rubrizonatus individuals were collected (17.2-88.8 mm SL) and spawning season was estimated as May-October. The von Bertalanffy growth parameters were estimated as L∞=88.72 mm, K=0.42 year−1 and t0=−1.24. In the gonads of all juveniles (22.0-50.1 mm SL, < 1 year old [n=45]), ovarian lumen was visible after an undiffrentiated phase, and spermatocytes were also detected among oocytes at primary growth stage, showing bisexuality. Sizes of minimum, maximum and 50% mature females were 39.4 mm, 77.2 mm and 41.8 mm SL, respectively (1-3 years old, n=180). Sex change to secondary male occurs at 8.2-79.3 mm SL (2-3 years old, n=6). Individuals undergoing sexual differentiation into primary males appeared at 32.8 mm (< 1 year old, n=1). Three small males aged 1 year old (62.7-63.6 mm SL), considered primary males, were collected. Ovarian lumen was observed in all testes (62.7-88.8 mm, 1-5 years old, n=45). Therefore, P. rubrizonatus is diandric protogyny and every individual can potentially become a primary male; this sexual pattern is unprecedented in Pseudanthias. Further research will investigate how P. rubrizonatus social structure affects the emergence of primary males.


    40.    ASIH Storer Ichthyology  Chondrocranial and Skeletal Labyrinth Morphology of Four Species of Living Sharks. Jordyn Neal*, California State Polytechnic University Humboldt; Samantha Rodrigues, California State Polytechnic University Humboldt; Allison Bronson, California State Polytechnic University Humboldt   jrn4@humboldt.edu

    The inner ear has long been used as a way to infer aspects of tetrapod ecology and behavior; however the connection between ear shape and ecology has not been tested in chondrichthyans and the endocranial anatomy of sharks is, overall, underdescribed. We used high-resolution CT scanning to generate renderings of the cranial and endocranial anatomy in four elasmobranchs: the Nurse Shark (Ginglymostoma cirratum), the Japanese Tope Shark (Hemitriakis japanica), the Horn Shark (Heterodontus francisci), and the Zebra Shark (Stegostoma fasciatum). From these renderings, we described and compared the anatomy of the inner ear and chondrocranium, using the Spiny Dogfish (Squalus acanthias) as a reference due to its ubiquity as an example in comparative vertebrate anatomy. Major differences are apparent between the skeletal labyrinths of these taxa, which may be ascribed to phylogeny or lifestyle. The size of the ear relative to the brain and cranium dramatically differs among these chondrichthyans, as does the diameter and angle of the semicircular canals. Based on the separation of the anterior and posterior semicircular canals, the degree of specialization for low frequency sound detection may also vary.


    41.    ASIH Storer Ichthyology  Comparative Anatomy of the olfactory organ in Rainbow Trout, Oncorhynchus mykiss. Nicole Rahman-Garnier*, California State Polytechnic University, Humboldt; Allison Bronson, California State Polytechnic University, Humboldt   nmr36@humboldt.edu

    Olfaction plays an integral role throughout the life of Rainbow Trout (freshwater Oncorhynchus mykiss) and is used for navigation, feeding, reproduction, and predator avoidance. Three primary types of chemoreceptor cells function in differentiating odorants in the aquatic environment: ciliated, microvillous, and crypt cells. Olfaction is critical for finding mates, and the anatomy of the olfactory organ likely differs between male and female individuals within the same population. To date, no studies have detailed variations in the gross anatomy of the olfactory rosette and microstructure of the chemoreceptor cells between O. mykiss sexes, age classes, and alternate life histories (anadromy vs. freshwater resident). We compared the distribution of olfactory receptor cells and supporting cells in the rosettes of two and three-year-old male and female O. mykiss using dissection and scanning and transmission electron microscopy. We also assessed the overall morphology and size of the rosette relative to the size and shape of the olfactory sac. The olfactory rosette changes in shape, becoming more elongate as both male and female fish grow, but males have a larger rosette relative to the size of the olfactory sac and their rosette becomes more acuminate at the rostral end. These data add to a growing body of knowledge on salmonid olfaction and serve as a foundation for additional studies comparing olfactory structures between resident and anadromous O. mykiss populations.


    42.    ASIH Storer Ichthyology  The skeleton of the smallest livebearer (Heterandria formosa) revealed through diaphonization and CT scanning. Tiffany Inbody*, Texas A&M University; Kevin W. Conway, Texas A&M University   t-inbody@tamu.edu

    The least killifish, Heterandria formosa, is the sole member of the genus Heterandria and simultaneously the smallest species of livebearer (Poeciliidae) and one of the smallest species of freshwater fish in the US. This tiny species inhabits swamps and the lower courses of rivers throughout the southern US, from the southern part of North Carolina to eastern Texas. Heterandria formosa exhibits superfetation, the simultaneous occurrence of more than one stage of developing offspring in the same individual, and is one of two genera of livebearers in North America to exhibit this life history strategy. Using a combination of clearing and double staining for bone and cartilage investigation and computer tomography scanning (CT), we document the osteology of adult male and female H. formosa, and the osteology of select pre-parturition embryos and post-parturition juveniles. We assess: (1) whether the adult skeleton of H. formosa exhibits signs of progenesis in comparison to other closely related livebearers; and (2) whether juveniles of H. formosa are born at a comparable developmental stage to that of other livebearers.


    43.    ASIH Storer Ichthyology  Heterodonty through ontogeny – Tooth development and replacement in the scale feeding fish Oligoplites saurus Bloch & Schneider 1801. Gabriel Afonso*, University of São Paulo; Katherine Bemis, NOAA Fisheries National Systematics Laboratory, Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution; Flávio Bockmann, University of São Paulo   gabrielvfa@usp.br

    Lepidophagy, the behavior of feeding on scales, evolved convergently in at least seven clades of teleost fishes. Oligoplites saurus, the Leatherjacket, is a scale-feeder that presents an interesting diet shift related to its odontogenesis. Feeding on scales primarily as juveniles, O. saurus has a heterodont dentition with hooked dentary teeth with spatulate tips in the labial row, and conical teeth in the lingual row. As adults, Oligoplites saurus feed primarily on fishes and the importance of scales decreases; hooked teeth are replaced by conical teeth. Despite its striking tooth morphology and odontogenesis, dentition of O. saurus is poorly known. To describe the tooth morphology and replacement in the oral jaws of O. saurus we evaluated different ontogenetic stages in a comparative approach using clearing & staining, dry skeletal preparations, histological sections, and CT scanning. Preliminary results indicate that conical teeth of lingual dentary row have a firm but flexible attachment to the bone, indicating an attachment through a collagenous ring. In contrast, hooked teeth have a looser attachment to the dentary and are more flexible at their bases, possibly presenting a partial collagenous attachment with an axis of rotation. Conical teeth that replace hooked teeth in adult specimens retain a loose attachment to dentary, maintaining a partial collagenous attachment even if changing tooth type. We will use Oligoplites saurus as a model to explore specializations for lepidophagy in other scale feeding taxa to help the identification of similar or different anatomical adaptations to this unusual behavior.


    44.    ASIH Storer Ichthyology  Development of Bony Scutes in White Sturgeon (Acipenser transmontanus). Melody Tew*, California State Polytechnic University, Humboldt; Allison Bronson, California State Polytechnic University, Humboldt   mpt21@humboldt.edu

    The neural crest is a hallmark of vertebrate development: an ectoderm-derived tissue that is the primordium to the spinal cord and a diverse array of organs. Ectomesenchyme - a neural crest-derived embryonic precursor to skeletal and odontogenic tissues - is present in both the cranial and trunk neural crest of cartilaginous fishes, but present only in the cranial neural crest of teleosts. Recent studies have described cranial neural crest derivatives in sturgeon (which have a bony dermal skeleton and a cartilaginous endoskeleton), but much remains unknown about their trunk neural crest derivatives, and no one has determined the developmental origin of their scutes. We used a combination of cell-fate tracing and histology in an embryonic growth series to describe the development of White Sturgeon scutes and assess whether the neural crest is involved in scute formation. These data provide insight into the development of skeletal tissues in the earliest actinopterygians.


    45.    ASIH Storer Ichthyology  A Quantitative Description of the Oral Tooth Diversity of the Lake Tanganyika Cichlid Radiation. Nicholas Peoples*, University of California, Davis   npeoples@ucdavis.edu

    In cichlid fishes, oral teeth are a direct point of contact between an individual and its environment. As such, teeth may face constant selection for specialization. The number, size, and shape of teeth influence feeding efficiency and are used to infer trophic specialization and characterize diverging morphs. However, prior work to characterize cichlid oral tooth diversity both within species and across taxonomic groups is largely qualitative, and large-scale quantitative comparisons are lacking. My research combines linear measurements and scoring of tooth traits (i.e., number of tooth rows) with geometric morphometric analysis of extracted teeth to produce a tooth morphospace of the Lake Tanganyika cichlid radiation. Preliminary results suggest the combination of these approaches captures the major axes of tooth diversity and improves upon the simple unicuspid or bicuspid descriptions commonly found in literature. This research will answer two major questions in cichlid tooth biology; what is the oral tooth diversity of a cichlid radiation, and what is the level of within-individual variation over many species? First, I will quantify within-individual variation in tooth shape by analyzing five sequential teeth from both the upper and lower oral jaw. Second, I will examine patterns of tooth trait and shape disparity between groups at different taxonomic levels. These results will evoke questions about the evolution of oral teeth in cichlids and serve as a valuable reference for future studies that include comparisons of tooth traits and shapes in cichlids.


    46.    ASIH Storer Ichthyology  Is Red Coloration in Chrosomus erythrogaster an Honest Signal? Julie Kastanis*, Austin Peay State University; Mollie Cashner, Austin Peay State University   jkastanis@my.apsu.edu

    Color can play a vital role in how fish interact within their environment by impacting social interactions, species identification, mate attraction, and predator-prey interactions. Carotenoids are the source of red and yellow pigments in fishes, and are synthesized by organisms such as algae, plants, fungi, and bacteria, thus fish must obtain them through diet. Red and yellow carotenoid-based coloration in both male and female Southern Redbelly Dace (Chrosomus erythrogaster) may reflect species identification as well as mate quality (i.e. is an honest signal), but the degree of variation is unknown. The purpose of this ongoing study is to investigate red/yellow coloration in Chrosomus erythrogaster as an indicator of overall individual health by comparing intensity and total coverage of carotenoid-based coloration, body condition, reproductive status, and presence of environmental stressors (i.e. external parasites, lesions, abnormal growths). We have found evidence that red coloration intensity and coverage is significantly different between breeding and non-breeding individuals, but little evidence for differences among individuals and the sexes.


    47.    ASIH Storer Ichthyology  Distribution and Habitat Associations of Peppered Shiner, Notropis perpallidus. Jessica Rath*, University of Central Arkansas; Joseph Miller, U.S. Fish and Wildlife; Ginny Adams, University of Central Arkansas; Reid Adams, University of Central Arkansas   jrath1@cub.uca.edu

    Originally described by Hubbs and Black in 1940, Notropis perpallidus, the Peppered Shiner, is a rare minnow endemic to eastern Oklahoma and southern Arkansas. Notropis perpallidus has been documented as inhabiting pools in warm, medium-sized rivers, and this habitat affinity can lead to increased risk of imperilment as small- to medium-sized rivers are subject to point and nonpoint pollution, urban sprawl, channelization, and damming. Peppered Shiner was designated as a Species of Greatest Conservation Need (SGCN) by the Arkansas Game and Fish Commission in 2015 and was petitioned for Federal listing during 2010. There has been a notable contraction in the range of Notropis perpallidus, having only been detected in the Saline River of Arkansas in recent years. We sampled 47 sites across the historic range in Arkansas, and the species was detected at only nine sites, all within the Upper Saline River. There was a positive association between detection of Peppered Shiner and irradiance, average depth, and presence of water willow at the microhabitat level, as well as site level variables of conductivity and turbidity. Our data suggest that Peppered Shiner may be extirpated, or nearly extirpated from the Ouachita, Caddo, and Little Missouri rivers, but still inhabiting the Saline River, with all detection sites occurring downstream of Benton, Arkansas. With additional sampling, we aim to further understand the distribution and ecology of Peppered Shiner in the Saline River, and we continue to sample in other parts of its historic range to aid conservation of this rare minnow.


    48.    ASIH Storer Ichthyology  Population Genetic Assessment of the Endangered Cumberland Darter (Etheostoma susanae). Hilary K. Canada*, Arkansas State University; M. Taylor Perkins, Tennessee Aquarium Conservation Institute; Anna L. George, Tennessee Aquarium Conservation Institute; Bernard R. Kuhajda, Tennessee Aquarium Conservation Institute; Brook L. Fluker, Arkansas State University   hilary.canada@smail.astate.edu

    The Cumberland Darter (Etheostoma susanae) is an endangered freshwater fish species endemic to the tributaries of the Cumberland River above Cumberland Falls in Kentucky and Tennessee. Once recognized as a subspecies of Johnny Dater (E. nigrum), E. susanae was elevated to species level based on morphological and mtDNA variation. Habitat degradation and modification is a concern for the species with its preference for slow-flow streams. Fragmented populations increase the risk of disrupting historic gene flow between tributaries which could result in genetically distinct populations. Fin clips were obtained from eight localities across the range of E. susanae for a total of 188 samples. An additional 86 samples were collected for comparative purposes from four localities for E. nigrum, two of which were thought to be potential hybridization zones for E. susanae and E. nigrum in the Cumberland and Upper Kentucky River drainages. Samples for both species totaled to 274 individuals obtained from 11 sample sites. To better understand the evolutionary history, patterns of genetic structure, and the potential for hybridization between E. susanae and E. nigrum, we analyzed data from both mitochondrial DNA (mtDNA) and microsatellite DNA loci. Microsatellites and mtDNA revealed no evidence of recent or ongoing hybridization or introgression between E. susanae and E. nigrum. Microsatellite data further revealed moderate to high levels of genetic structuring among several populations of E. susanae. Results will be combined with ongoing RADSeq data analyses, providing a comprehensive genetic roadmap that will be useful for conservation and management strategies involving E. susanae.


    49.    ASIH Storer Ichthyology  Why so mad: an evolutionary analysis of lineage diversification among madtom catfishes (Siluriformes: Ictaluridae:Noturus). Brittany McCall*, Arkansas State University; Jacob Egge, Pacific Lutheran University; Brook Fluker, Arkansas State University   bmccall1092@gmail.com

    Madtom catfishes (Ictaluridae: Notutrus) are the most speciose genus of North American catfishes. The species richness of Noturus has been attributed to a rapid diversification associated with a decrease in body size that has made resolving deep relationships within the genus difficult due to incomplete lineage sorting. Past phylogenic hypotheses based on a combination of mitochondrial markers, nuclear markers, and morphology have resolved some relationships and served as the basis for identifying cryptic species. These same analyses, however, inconsistently recover or report low support for several species groups and point to the potential for additional cryptic diversity. The objective of this study was to reevaluate genus-level phylogenetic hypotheses for Noturus to better resolve taxonomic relationships, assess additional cryptic diversity, and improve the available data on the genus. Tissue samples of Noturus species were obtained through a combination of field collection and gifted material from natural history collections. Restriction site associated DNA sequencing (RADseq) data was generated using a variety of data filtering approaches and analyzed with phylogenetic methods. Our resulting phylogenies recover novel relationships among taxa, corroborate previously identified patterns suggestive of cryptic diversity, and fail to recover some previously hypothesized subclades. This robust phylogenetic framework, combined with a relatively comprehensive understanding of the natural history of Noturus provides a unique opportunity to assess the response of a phenotypically conservative, yet genetically diverse clade to a changing environment through time.


    50.    ASIH Storer Ichthyology  Comparing Gene Expression Profiles of Killifishes With Different Life Histories (Cyprinodontiformes: Nothobranchiidae). Chi Jing Leow*, Southeastern Louisiana University; Kyle Piller, Southeastern Louisiana University   chijingleow97@gmail.com

    The African Turquoise Killifish (Nothobranchius furzeri: Nothobranchiidae) is a recently developed model organism used in the study of ageing and age-related diseases. Various strains of the Turquoise Killifish possess life spans between 10 and 31 weeks, with the GRZ strain being the shortest-lived vertebrate species. The expedited life-cycle is related to their occupancy of seasonal, ephemeral habitats in east Africa. Within the Nothobranchiidae, many species/genera are annual species, completing their life-cycle in less than a year, however others possess non-annual or facultative/semi-annual life-histories. DNA repair genes play a strong role in the survival of an organism and this is based on the idea that longer-lived organisms require long-term DNA repair in contrast to shorter-lived organisms. Therefore, we tested for differential expression of DNA repair genes across nothobranchid fishes with different life-histories. We hypothesized that non-annuals and facultative annuals would possess higher levels of gene expression in DNA repair genes relative to annual species. To accomplish this, livers were harvested from six species of nothobranchid fishes from Nothobranchius, Epiplatys, Aphyosemion, and Fundulopanchax. Samples were prepped and sequenced using a QuantSeq approach. The recovered data were submitted to differential gene expression analysis. The results of this analysis will be discussed.


    51.    ASIH Storer Ichthyology  Investigating the Biologic and Anthropogenic Soundscapes of Biscayne Bay. Abigail M Tinari*, University of Miami - RSMAS; Neil Hammerschlag, University of Miami - RSMAS   a.tinari@umiami.edu

    The marine soundscape has fundamentally changed since the industrial revolution. Waters once dominated by biological and geological sounds are now overrun by anthropogenic noises. Sound propagates fast and far underwater, carrying sensory information farther than light or chemicals. Animals use sound to aid in communication, reproduction, navigation, foraging, territorial defense, and predator detection strategies. Most human-made noises overlap with frequencies many animals use to hear and communicate. Due to this overlap, anthropogenic noises may cause a variety of alterations in behavior, foraging, and other communication patterns or may completely mask predator and prey cues. Despite being near a major metropolitan area, Biscayne Bay, on the shores of Miami, FL, does not have a documented soundscape. Underwater hydrophone listening stations were placed along an urban gradient starting in 2018 to evaluate spatial and temporal patterns in biological and anthropogenic noise. We hypothesize hydrophones located closer to Miami will have greater amounts of anthropogenic noise while those farther from Miami will be dominated by biological sounds. The increase in anthropogenic noise is predicted to lead to a decrease in biological sounds. In line with our previous prediction, we hypothesize that biological sounds will increase during weekdays and decrease during the weekends or holidays due to an increase in anthropogenic noise. We will also investigate the relationship of biological sounds on a diel cycle, with predictions that fish chorusing will increase at night while snapping shrimp will be more active during the day.


    52.    ASIH Storer Ichthyology  Early Invasion Dynamics of the Asian Swamp Eel Amphipnous cuchia in New Orleans, Louisiana. Susan Thomassie*, Biological Sciences, Loyola University New Orleans; Olivia M. Guerra*, Environment Program, Loyola University New Orleans; Regina Coeli Campion*, Biological Sciences, Loyola University New Orleans; Frank Jordan, Biological Sciences & Environment Program, Loyola University New Orleans   jordan@loyno.edu

    Cuchia (Amphipnous cuchia) is an air-breathing, synbranchiform fish native to Southeast Asia. Like other swamp eels, Cuchia is a nocturnal, fossorial, opportunistic predator that is capable of travel over land and can tolerate a variety of harsh environmental conditions. In June 2019, Cuchia was discovered in Bayou St. John, an urban waterway in New Orleans that is hydrologically connected to Lake Pontchartrain. Data on abundance, distribution, and ecology of Cuchia are needed to characterize early invasion dynamics and inform control and management of this recently introduced species. To help address this need, we used dip nets, seines, throw traps, leaf packs, minnow traps, and inspection of root mats to sample Cuchia and associated aquatic communities at 12 sites in Bayou St. John, 3 sites in the adjacent City Park lagoons, and 2 sites in Lake Pontchartrain during the summers of 2019, 2020, and 2021. We collected several age and size classes of Cuchia in all three years, including young-of-year, which indicates the presence of a successfully-reproducing population. The distribution of Cuchia in Bayou St. John increased modestly over the sampling period, but Cuchia has not yet been detected in City Park or Lake Pontchartrain. However, preliminary lab experiments indicate Cuchia is tolerant of salinities up to at least 10 ppt, suggesting that Cuchia are physiologically capable of surviving in the Lake. The potential for Cuchia to spread into Lake Pontchartrain is troubling, as the Lake provides an avenue for further dispersal into nearby drainages, including the Mississippi River.


    53.    ASIH Storer Ichthyology  Variation in Fish Communities of Boston Mountain Streams in the Ozark National Forest. Jackson Pav*, University of Central Arkansas; Ginny Adams, University of Central Arkansas; Reid Adams, University of Central Arkansas   jpav@austin.rr.com

    The Boston Mountains of the Ozark-St. Francis National Forest have a rich history of conservation spanning hundreds of years. This Pennsylvanian Period mountain range yields high amounts of sandstone and shale, resulting in fish communities unique to the state of Arkansas. Thirty-five sites across Big and Little Piney creeks, Illinois Bayou, Mulberry River, and Lee Creek watersheds were plotted in species relative abundance space using nonmetric multidimensional scaling to examine fish community level variation among sites. Fish community composition was significantly different across watersheds (multi-response permutation procedure, p<0.001). An indicator species analysis identified ten fish species as significant (p<0.05) indicators of watersheds including Etheostoma pulchellum 1 in Big and Little Piney creeks, Micropterus dolomieu in Illinois Bayou, Pimephales notatus in Mulberry River, and Fundulus catenatus in Lee Creek. Stream catchment size was one of the strongest drivers in determining relative abundance of species per site. Additional variation is likely related to abiotic factors such as substrate and physicochemical properties. Active land use techniques and its impacts on stream ecology and fish community structure will be discussed. This study will provide useful insight into community composition and habitat associations of fishes in streams of the Boston Mountains.


    54.    ASIH Storer Herpetology  Cell Types in the Olfactory Organs of a Plethodontid Salamander. Giuseppina Sole Lanzilli*, Cal Poly Humboldt; John Reiss, Cal Poly Humboldt; Karen Kiemnec-Tyburczy, Cal Poly Humboldt   gl138@humboldt.edu

    The transition from water to land is one of the major events in vertebrate evolution. This change had important consequences for sensory systems, including olfaction, which is extensively used for feeding, social and reproductive purposes. In living amphibians, the olfactory system consists of the main olfactory cavity (MOC) and the vomeronasal organ (VNO), which lies in a lateral diverticulum. The olfactory ultrastructure in amphibians is complicated and varies from order to order but generally, the MOC cell types may change after metamorphosis, but cell types in the VNO do not change (though the precise cell types present vary among species). We examined the cell types of the olfactory organs of Ensatina eschscholtzii (Urodela: Plethodontidae: Plethodontinae). Histological sections revealed the presence of a thick olfactory epithelium with olfactory cilia on the anterior region, and a thinner epithelium with non-olfactory cilia in the posterior part of the MOC, surrounded by both secretory and non-secretory supporting cells, which constitute the main olfactory epithelium (MOE). The VNO consists mainly of ciliated cells. Electron microscopy confirmed this result, showing the 3D distribution of the diverse morphologies of the two kinds of cilia inside the cavity. These results are similar to those obtained for Plethodon cinereus(Dawley, 2017), also a completely terrestrial plethodontid: the presence of nasolabial glands (unique to plethodontids), a thick olfactory epithelium, a nasolacrimal duct that opens to the vomeronasal organ, and the VNO replaced by non-sensory epithelium posteriorly, where it continues as the palatal groove.


    55.    ASIH Storer Herpetology  Molecular evolution and expression of visual pigments across urodeles. Emily Bierbaum*, University of Tulsa; Matthew Toomey, University of Tulsa; Ronald Bonett, University of Tulsa   emily.bierbaum@gmail.com

    Salamanders inhabit a wide variety of aquatic and terrestrial environments with different light regimes that impose evolutionary pressures on the visual system. A commonly observed pattern in visual ecology, is that visual pigments tune to wavelengths of light available in the environment. Visual pigments consist of a retinoid chromophore and an opsin protein. Spectral tuning can occur in two ways: amino acid substitutions in the opsin protein or a change in the chemical structure of the chromophore. Two types of chromophores are present in vertebrates, as well as five classes of opsin genes, but in amphibians one of the opsin genes is lost. Opsins vary in peak spectral sensitivity, such as short-wavelength, middle-wavelength, and long-wavelength. Switching the chromophore component from vitamin A1 into vitamin A2 causes a red-shift in that peak sensitivity. The enzyme cyp27c1 mediates the switch between chromophore types by converting vitamin A1 into vitamin A2. Animals that inhabit clear aquatic habitats and terrestrial environments typically utilize the vitamin A1 derived chromophore, while a higher proportion of vitamin A2 is found in organisms that inhabit aquatic habitats with highly variable light, such as turbid waters. HPLC analysis of retina extracts were performed to determine chromophore type, as well as transcriptional analyses to examine opsin gene repertoires across salamanders with an emphasis on testing ecology and life cycles. Our talk will cover variation and visual ecology and its relationship to biochemical properties of visual pigments in salamanders.


    56.    ASIH Storer Herpetology  Tale of Two Mudpuppy Populations: Impacts of TFM on Ohio's Second Largest Salamander. Ryan Wagner*, Ohio State University; William Peterman, Ohio State University   ryanbwagner97@gmail.com

    Freshwater environments are among the most imperiled ecosystems on earth due to anthropogenic degradation. Among the most at-risk freshwater organisms are amphibians, which have experienced global declines during the last several decades. The Common Mudpuppy (Necturus maculosus) is a large-bodied, fully aquatic salamander that inhabits both lentic and lotic environments. Despite their wide distribution, recent population declines have been documented. Perhaps the most significant threat to mudpuppy populations is the use of 3-trifluoromethyl-4-nitrophenol or TFM, a chemical lampricide used by the US Fish and Wildlife Service to control the invasive sea lamprey (Petromyzon marinus) in the Great Lakes and its tributaries. TFM is known to cause a 29% decline in mudpuppy populations immediately following treatments. In this study, we aimed to better understand the long-term effects of TFM applications on mudpuppy populations in Ohio. We conducted a mark-recapture study of two mudpuppy populations, one regularly exposed to TFM and the other unexposed. We estimated population size (N) and survival probability (phi) in both populations using mark-recapture. Both analyses were done using a Bayesian framework in JAGS. Estimated population size for the exposed site was 193.9 ∓ 25.3, while population size for the unexposed site was 334.2 ∓ 21.6. Estimated survival for the exposed site was 0.84 ∓ 0.05, while estimated survival for the unexposed site was 0.92 ∓ 0.01. Population size and survival were higher for the TFM-unexposed site compared to the TFM-exposed site. This suggests TFM may have long-term impacts on mudpuppy population size and survival.


    57.    ASIH Storer Herpetology  Drivers of Life History Variation in a Paedomorphic Salamander. Jessica Sandoval*, Southern Illinois University Edwardsville; Thomas Anderson, Southern Illinois University Edwardsville   jesando@siue.edu

    Phenotypic variation is ubiquitous among animals and is thought to provide an evolutionary advantage for species living in variable environments. Paedomorphosis, or the retention of juvenile traits in sexually mature adults, is a model system for understanding the ecological causes of phenotypic variation. In the facultatively paedomorphic mole salamander (Ambystoma talpoideum), the species’ complex life cycle can follow three pathways that ultimately lead to the expression of two discrete adult phenotypes. An individual may undergo traditional development from egg to aquatic larva but will (1) remain in the water as a reproductive, gilled adult (i.e., paedomorph), (2) metamorphose into a terrestrial adult, or (3) delay metamorphosis and overwinter in an immature state in ponds, eventually developing into either the terrestrial or aquatic phenotype the subsequent year. We examined the influence of species interactions on phenotypic variation by assessing how larval salamander and predator densities impacted life history outcomes in mole salamanders. In May and December of 2013-2015, we sampled twenty-one ponds in western Kentucky using minnow traps and dip-nets. Increased larval densities in the spring resulted in greater numbers of overwintering larvae the following winter. There is a weak negative correlation between larval densities and paedomorph occurrence. Predator densities did not have a strong impact on production of paedomorphs or overwintering larvae. We hypothesize that inter and intra-specific competition among larval salamanders led to reduced growth rate and an inability to reach the size required for maturation, which resulted in an increase in overwintering larvae and decrease in paedomorphs.


    58.    ASIH Storer Herpetology  Comparison of Nocturnal and Diurnal Survey Methodologies for Plethodontid Salamanders in Western Oregon. Jasmine Williamson*, Oregon State University; Chris Cousins, Oregon State University; Tiffany Garcia, Oregon State University   jasmine.m.williamson@gmail.com

    Accurate estimation of wildlife and fisheries populations is dependent on effective survey methodologies, which are complicated by unique life histories or low densities. Population studies for terrestrial salamanders are uniquely difficult because they retreat to underground or within-wood refugia during inhospitable conditions, resulting in as little as ten percent of the population surface active at any given time. Research shows little consensus on the most effective methods for terrestrial salamander surveys. Furthermore, detection probabilities vary based on weather, surface conditions, and activity patterns of the species. This study aims to quantify the difference in terrestrial salamander detection rates between nocturnal and diurnal area-constrained active searches in the western Oregon Cascades. Twelve sites paired with HOBO environmental data loggers within HJ Andrews Long-Term Ecological Research (LTER) forest was sampled in spring of 2022, with plans to repeat surveys in the fall of 2022 to assess seasonal differences in detection probability. Our hypothesis that nocturnal surveys would result in higher detection rates relative to diurnal surveys was supported. Comparing the detection rates of survey methodologies for terrestrial salamanders illuminates the efficacy of survey timing within the Western Cascades and beyond. Knowing the relationship between diurnal and nocturnal surveys will be helpful in studies where nocturnal surveys cannot be performed due to a multitude of safety concerns, including unsafe post-fire conditions, post-logging conditions, and landslides.


    59.    ASIH Storer Herpetology  Suburban salamanders: the status and origin of slender salamanders of Oregon west of the Cascade Range. Clare Yang*, Pacific University; Laura Guderyahn, Northwest Ecological Research Institute; Lauren Chan, Pacific University   chan5416@pacificu.edu

    The Oregon slender salamander, Batrachoseps wrighti, occurs in the northern Cascade Range of Oregon where they are typically associated with the large decaying logs of old-growth and mature forests. They are a federally listed species of concern, state-listed sensitive species, and are classified as “vulnerable” on the IUCN Red List. Recently, several populations of Oregon slender salamanders have been found outside of their known range near the Portland Metro area west of the Cascade mountains. We use species distribution models and genomic SNP data to determine whether these populations are evolutionary relicts, or alternatively, more recent human-mediated introductions. We reconstruct paleo-distributions and current distributions given confirmed Oregon slender salamander localities. We use population genetic and phylogenetic analyses alongside coalescent-based simulations to determine the origin of these newly discovered populations and to assess the effective population size and genetic diversity of each population as indicators of health and demographic isolation. We additionally report on the identification and characterization of an established, introduced population of the California slender salamander far outside its native range in western California and Oregon within the range of the Oregon slender salamander. We discuss our results as they relate to the conservation and management of the Oregon slender salamander.


    60.    ASIH Storer Herpetology  Temporal variation in the functional diversity of amphibians from the Sierra Madre del Sur, Guerrero, Mexico. Víctor Hugo Colín-Martínez*, Universidad Nacional Autónoma de México; Leticia Margarita Ochoa-Ochoa   victorhugo@ciencias.unam.mx

    In this study, the functional diversity of amphibians was analyzed at the beginning, middle and end of the rainy season in remnants of semi-evergreen forest for two different landscapes in Guerrero, Mexico — Costa Chica and Costa Grande. Twenty-seven species of Anurans and one species of Gymnophiona were recorded. The most abundant species were Tlalocohyla smithii and Exerodonta sumichrasti; the least abundant species were Hypopachus variolosus and Dermophis oaxaceae. 10 functional groups were observed in Costa Grande and 11 in Costa Chica. During the three sampling seasons, a change in the proportion of functional groups was observed. Some groups persisted throughout the rainy season and others appeared or disappeared, as reflected in the values of functional diversity. Through a generalized linear model of the Poisson family, the functional richness of Costa Grande was explained mainly by environmental factors such as weekly precipitation, followed by accumulated precipitation, the rainy season, temperature, and humidity. For Costa Chica, the model showed a significant contribution for functional richness by canopy cover, followed by temperature, weekly precipitation, and humidity. No significant results were obtained in any of the models regarding functional equality and divergence. The present work contributes to the knowledge of amphibian functional diversity patterns in tropical environments, providing current information for the state and setting precedents for the development of future ecological studies and amphibian conservation plans.


    61.    ASIH Storer Herpetology  Impacts of the Environmental Microbial Species Pool on the Microbiota-Gut-Brain Axis in Larval Amphibians. Kyle Emerson*, Duquesne University; Dr. Sarah Woodley, Duquesne University   emersonk@duq.edu

    Microbes present in the immediate local environment at birth/hatching are the first to colonize the vertebrate gastrointestinal tract and form the gut microbiota. The gut microbiota participates in a symbiotic relationship with the host that influences many aspects of physiological development, including neurodevelopment through the microbiota-gut-brain (MGB) axis. Investigations of the MGB axis have found that manipulations of the gut microbiota can impact neural signaling pathways associated with cognitive and behavioral impairments. In addition, evidence suggests disrupting microbial colonization in early life can be particularly detrimental. Here, I investigated whether manipulating the environmental microbial species pool impacted relative brain size, relative brain shape and behavior in newly hatched Northern Leopard Frog tadpoles (Lithobates pipiens). Amphibians are an excellent model to study the impacts of environmental factors on the gut microbiota because they develop completely in the external environment. Further, investigations into the MGB axis in ectothermic vertebrates remains a pertinent knowledge gap. I hypothesized that microbes present in the local environment during early development will impact brain development and behavior in tadpoles. I raised tadpoles in sterilized lab water seeded with 25% natural pond water, or 25% autoclaved natural pond water to reduce the abundance and diversity of microbes present in the local environment. Tadpoles raised in autoclaved natural pond water had relatively larger brains, relatively narrower medullas, and decreased locomotory activity in response to novel stimuli. These results support my hypothesis that the microbes present in the local environment impact neurodevelopment and behavior in a larval amphibian model.


    62.    ASIH Storer Herpetology  Quantifying Habitat Degradation and Restoration Potential of Breeding Sites for the Imperiled Carolina Gopher Frog (Rana Capito). Tucker Stonecypher*, University of Georgia, Odum School of Ecology; Linda Lee, University of Georgia, Savannah River Ecology Laboratory; Stacey Lance, University of Georgia, Odum School of Ecology   ets91825@uga.edu

    The southeastern US is one of the most biodiverse regions in North America, largely due to fire-maintained landscapes, where various taxa have evolved amongst regular fire disturbance. The imperiled Carolina gopher frog (Rana capito) is one of many pond breeding amphibian species that have experienced precipitous declines due in part to anthropogenic alterations of natural fire regimes. Gopher frogs migrate from sandy uplands to breed in ephemeral open canopied wetlands with an abundant herbaceous component. Periodic fire kills woody vegetation that would otherwise block sunlight, accumulate non-pyrogenic litter, and reduce wetland hydroperiods through excessive evapotranspiration. Decades of fire suppression has caused many wetlands to become overgrown with woody vegetation, thus inhibiting herbaceous growth. Current wetland restoration practices largely rely on passive revegetation from a viable seedbank. To better understand R. capito declines and potential for restoration success, we measured wetland canopy closure rates of extant and extinct breeding wetlands on the US Department of Energy Savannah River Site across 70 years using historic aerial imagery and conducted seed germination trials from a subset of these wetlands. We collected soil at a depth of 10cm and induced seed germination under moist growing conditions for 7 months. We compared species composition and wetland indicator status in our germination trials to present standing vegetation and to similar data collected at these wetlands in 1989. Readily germinable plants expressed in our trials represent the suit of species likely to respond to restoration and provide important insight on initial community trajectories of restored ephemeral wetlands.


    63.    ASIH Storer Herpetology  American toad (Anaxyrus americanus) Dorsal Coloration Across an Environmental Gradient. Mariah Mack*, Southern Illinois University Edwardsville; Lynne Beaty, Penn State- The Behrend College   mariahnmack97@gmail.com

    Adaptive coloration in amphibians is widespread and aids in camouflage, communication, and thermoregulation. Understanding the environmental factors that contribute to color variation is important for predicting how changes in climate and habitat parameters may alter amphibian fitness. Studies on toad coloration have focused on genetic elements, dorsal spot patterns, and juveniles, but less is known about the relationship between adult toad coloration and environmental conditions. The goal of this study was to examine dorsal color variation in adult American Toads (Anaxyrus americanus) in Erie County, Pennsylvania, USA, to determine how environmental and morphological factors influence coloration. We conducted visual surveys to sample adult toads across a habitat gradient and recorded several potential predictor variables (i.e., site elevation, substrate type, snout-vent length, and body surface temperature). We calibrated photographs of each toad and quantified red (R), green (G), and blue (B) color values within seven dorsal body regions. We summarized RGB values for each dorsal body region using a principal component analysis and used model selection approaches to select between models containing different predictor variables. The most supported model to explain the variation in color of all dorsal body regions contained only site elevation. On average, the body regions of all toads from higher elevation sites were darker than those from lower elevations, but the amount of variation in dorsal coloration accounted for by elevation was low. Our results suggest that the factors driving variation in toad dorsal coloration are complex, but that this trait is potentially sensitive to environmental changes.


    64.    ASIH Storer Herpetology  Changes in Anuran Behavior and Neurodevelopment From Hatching through Metamorphosis. Gia LaSalle*, Moravian University; Sara McClelland, Moravian University   lasalleg@moravian.edu

    The vertebrate brain is a complex organ that is responsible for controlling organismal performance. To enhance the fitness of animals living in different environments, the brain is highly plastic. Brain plasticity is the ability of the nervous system to change in response to environmental stimuli through the reorganization of functions and structure. While we need to understand how the brain is being impacted by different environmental conditions, it is also important for us to understand how the brain naturally develops. By monitoring macroscopic morphological changes throughout larval and juvenile neurodevelopment, it will provide us with a baseline understanding of how portions of the brain change during different life history stages in amphibians and will help prevent us from misinterpreting the neurosensory development of animals in ecological studies. This research is an observational study of changes in behavior and brain morphology across different life history stages in an anuran model (premetamorphosis, prometamorphosis, metamorphic climax, and juveniles). Behavioral assays were conducted, life history stages confirmed, and brain morphology analyzed. We hypothesized that changes in the brain will lead to behavioral changes across development. In our first experiment, we found the brains of tadpole and juvenile frogs separate into two distinct morphologies using principal components analysis. There were changes in the telencephalon, diencephalon, optic tectum, and medulla. This study will provide important data that will give us insights into how changes in neurodevelopment correlate with changes in behavior across vertebrate development.


    65.    ASIH Storer Herpetology  Genetic Differentiation of a 70-80 Year Colonization of Mediterranean Geckos (Hemidactylus turcicus) at the University of Oklahoma. Meryem Assaoui*, University of Central Oklahoma; Lauren Branham, University of Central Oklahoma; Kai Williams, University of Central Oklahoma; Allyson Fenwick, University of Central Oklahoma   afenwick@uco.edu

    Mediterranean geckos (Hemidactylus turcicus) have spread around the world in commensal relationships with humans. In the central U.S., central Oklahoma is near the northern end of the range. Cold winters seem to restrict activity, making independent colonizations easy to distinguish. Work at the University of Oklahoma (OU) is part of a study comparing multiple sites in this region. Geckos colonized OU in the 1940s or 1950s via escape from research labs at one of two sites in the center of campus. Geckos are found across most of the city of Norman. We have sampled over 250 individuals from almost 30 buildings. We found low genetic diversity, evidence of bottlenecks, and multiple genetic clusters. In contrast to more recent colonizations such as the University of Central Oklahoma (1962–1965 and mid-1980s–1997), we find a lack of geographic pattern in the genetic clusters of OU geckos. We find that the history of colonization may have more impact on genetic differentiation than environmental factors. We are continuing to expand the geographic range of sampling in order to better characterize patterns of differentiation and evaluate dispersal within colonizations.


    66.    ASIH Storer Herpetology  Super Labeling of Supralabials and Other Advantages of a Network-Based Analysis of Pholidosis. Isaac Krone*, Museum of Vertebrate Zoology, University of California Berkeley   isaacwkrone@gmail.com

    While herpetologists often rely on the relative sizes, positions, and numbers of scales (pholidosis) to distinguish squamate taxa, little attention has been paid to how scalation evolves in systematic detail. Here, I present a comparative framework for pholidosis which models scalation patterns as networks, allowing the entire pattern of pholidosis to be analyzed rather than split into discrete characters. Scales represent vertices in the network, while the contact points between scales represent edges. These basic components can be expanded upon to include information about suture completion, scale size, color, and other properties. In concert with this representation, I present a graph edit distance based framework for comparing these pholidosis networks, allowing them to be systematically analyzed analyzed within a comparative context. I then demonstrate the utility of these networks by applying the technique to dibamid lizards, presenting a pholidosis-network based phylogenetic hypothesis for the family Dibamidae and analyzing the relationship between size and head scalation pattern within the group.


    67.    ASIH Storer Herpetology  Species Delimitation of a Dwarf Horned Lizard Population (Phrynosoma hernandesi): Genetic Data Support the Single Species Hypothesis. Julianna Hoza*, University of Washington; Hayden Davis, University of Washington; Adam Leache, University of Washington   juliannahoza@gmail.com

    Species boundaries are difficult to delimit using morphology alone, and genomic data can provide important evidence for understanding the connectivity between populations or species. A recently described horned lizard, Phrynosoma diminutum, is miniaturized relative to the surrounding populations of the Greater Short-horned Lizard (P. hernandesi). Phrynosoma hernandesi is a wide-ranging species with substantial morphological and genetic variation throughout its range, and despite the obvious size difference between P. diminutum and P. hernandesi, a complete lack of gene flow between these populations seems unlikely since there are no clear barriers to dispersal. To determine the extent of gene flow between populations and to test the hypothesis that P. diminutum is a distinct species, we used genomic data to compare P. diminutum to surrounding populations of P. hernandesi. Using 3,000+ genetic markers distributed throughout the genome, we found that P. diminutum does not form a distinct evolutionary lineage and is only weakly differentiated from nearbyP. hernandesi populations. Comparisons of genetic differentiation among all 17 species of horned lizards using FST values provides further evidence that the low levels of divergence observed in P. diminutum are reflective of population-level and not species-level divergence. Therefore, we propose that P. diminutum be synonymized withP. hernandesi. Furthermore, we show how genomic data can be used to avoid artificially inflating biodiversity estimates by more accurately testing species boundaries, thus allowing managers to make precise decisions for wildlife and whole ecosystem conservation.


    68.    ASIH Storer Herpetology  The Heat is On: A Comparative Analysis of Two Different Methods for Measuring CTmax in Squamates. Sawyer Markham*, New College of Florida; Lila Marlowe, New College of Florida; Tiffany Doan, New College of Florida   sawyervmarkham@gmail.com

    As climate change continues to threaten biodiversity around the world, time is running out to protect many species from extinction. Reptiles, especially lizards, are among the most threatened species, and over twenty percent of all lizards are expected to face extinction as temperatures increase globally. Due to their abundance and small size, testing the critical thermal maxima (CTmax) of lizards has proven to be an effective strategy for determining their likelihood of survival as temperatures continue to rise, however there is no general consensus as to which method of testing CTmax is the most precise. Hemidactylus mabouia is an invasive and highly abundant species of gecko in South Florida and limited information is available on their thermal tolerance. We collected these geckos in Sarasota, Florida, and tested their CTmax by using two different conventional measurements: the demonstration of loss of normal function in the lizard by panting and muscular spasms. We found that the data recorded for the temperature at which a gecko pants was significantly more variable and lower than that of the temperature at which muscular spasms were observed, with average of 38.2 C (pants) versus 42.2 C (spasms). Based on these results, we conclude that testing CTmax by way of observing muscular spasms is the more precise method of determining the critical thermal maxima of lizard species.


    69.    ASIH Storer Herpetology  Morphometric Analysis of Fence Lizards (Sceloporus undulatus Species Group): Are Phylogenetic Groups Morphologically Distinct? Aracely Herrera*, University of Washington; Adam Leache, University of Washington; Sonal Singhal, California State University, Dominguez Hills   ah0120@uw.edu

    Fence lizards in the Sceloporus undulatus species group have a large distribution in the United States and northern Mexico. Across their range, they show high levels of geographic variation in body size and coloration. One clade in the group is responsible for causing taxonomic uncertainty, S. “undulatus”. Phylogenetic analyses of mitochondrial and nuclear DNA support at least five species in S. “undulatus”, whereas morphological data support one species with up to 10 subspecies. Previous morphological studies have focused on describing new species and subspecies, but correlations between morphology and phylogeny have not been tested using multivariate statistical analyses of morphological data. This study uses morphometric analyses to test if phylogenetic groups are also morphologically distinct. We measured >400 specimens with an emphasis on populations in the Western USA where morphological, genetic, and taxonomic variation is highest. Multivariate statistical analyses were conducted using 15 traits, including five head shape and body size characteristics, four scale counts, and six color pattern traits. We used a new phylogenetic framework estimated using genomic data to categorize the morphological samples. To test if the phylogenetic groups are morphologically distinct, we performed principal component and classification analyses. Determining if phylogenetic groups are morphologically distinct is important for conservation and taxonomy.


    70.    ASIH Storer Herpetology  Watery going to do about Drought Impacts on Lizards?: Osmoregulation of Blunt-Nose Leopard Lizards and Water Availability in their Prey. Tess McIntyre*, California Polytechnic State University; Savannah Weaver, California Polytechnic State University; Taylor Van Rossum, California Polytechnic State University; Emily Taylor, California Polytechnic State University   temcinty@calpoly.edu

    Endemic to California’s arid Central Valley, endangered Blunt-nosed Leopard Lizards (Gambelia sila) have adapted to xeric conditions but like many desert lizards remain at-risk to extinction due to climate change. Understanding how G. sila maintains water balance through cutaneous evaporative water loss (CEWL) and water intake from prey can help inform endangered reptile conservation strategies in warmer, drier environments. We hypothesized that seasonal changes in climate drive variation in prey water quantity and water loss across the skin, and thus hydration for insectivorous G. sila. To study the lizards’ osmoregulation, we measured CEWL and plasma osmolality of the same induviduals throughout the field season. We also collected invertebrate specimens and quantified water content. We found great variability in lizard hydration during the field season. Our data suggests a chain of hydration, where more rainfall contributes to higher invertebrate water content. These invertebrates are then consumed by G. sila, increasing their hydration. CEWL, while low, represents a major route of water loss for G. sila, and the large amount of time they spend in comparatively humid rodent burrows may help prevent water loss. As the effects of climate change intensify, megadroughts may intensify hydric pressure on G. sila and other sensitive species, so it will be important to identify which prey species contain the most water—making them integral to survival.


    71.    SSAR Rabb  Tadpole Developmental Rate, Survival, and Behavior when Exposed to Microplastics During Development. Scott Kornfeind*, Moravian University; Sara McClelland, Moravian University   kornfeinds@moravian.edu

    Microplastics (MPs) are defined as plastic fragments between 0.1 µm and 5 mm in dimension. MPs are a very common pollutant found in multiple environments throughout the world. MPs are increasingly found in ponds, lakes, and wetlands, where toads, frogs, and tadpoles frequently inhabit and feed extensively in, leading to direct exposure to the MPs present in the environment. These pollutants have been shown to have a number of adverse effects on many species, but in depth knowledge on how they affect amphibians is still not well researched. We hypothesized that exposing tadpoles to MPs will affect their developmental rate, behavior, and survival. To test this hypothesis, we exposed tadpoles to an environmentally realistic concentration of MPs (0.5 ppb) that are 34-50 µm in size during larval development. We are measuring how developing in the presence of MPs will impact developmental rate, survival, and behavior of tadpoles. Results from this study will provide evidence of how MPs affect amphibian development in contaminated habitats.


    72.    SSAR Rabb  Using Planarians as a Model for Amphibian Biology: Measuring Tissue Regeneration in Pesticide Contaminated Water. Joelis Rodriguez Santos*, Moravian University; Sara McClelland, Moravian University   joelis.marie10@gmail.com

    Amphibians are at high risk from environmental contaminants due to their highly permeable skin and reliance on both aquatic and terrestrial habitats. Malathion, a man-made organophosphate, is commonly used as an insecticide in agriculture and causes adverse effects on animals and ecosystems. We are interested in understanding how common environmental pollutants are impacting amphibian biology. Freshwater planarians (Dugesia tigrina) are used as bioindicators for freshwater environments, and make an ideal model organism for better understanding how environmental contaminants are impacting amphibians. Similar to amphibians, planarians have advanced central nervous systems (albeit more simplistic), have been shown to be able to learn and remember, and have the ability to regenerate. In this experiment, we used planarians to determine how exposure to the organophosphate malathion would impact tissue regeneration. To do so, we exposed planarians to either a vehicle control or to 1 µg/L malathion. After being exposed to treatments for 3 days, the head was split from the body, planarians were returned to treatments, and regeneration was observed for two weeks. Pictures were taken three times a week. ImageJ was used to measure the area of tissue regenerated over time. While analysis is ongoing, we are hopeful that this study can give us insights into how exposure to environmentally realistic concentrations of an environmental toxin might impact the ability to regenerate tissues. This work has implications for amphibians and whether their ability to regenerate tissue will be impacted by exposure to organophosphorus pesticides.


    73.    SSAR Rabb  Phylogeography of Northwestern Salamanders (Ambystoma gracile) in the Olympic Mountains. Adam Leaché, University of Washington; Torsten Watkins*, Wenatchee Highschool   torstenwatkins@gmail.com

    The Olympic Mountains of Washington state function as an ’island’ containing over a dozen endemic species and many isolated populations of species with broader distributions. The Cordilleran ice sheet helped shape the biogeography of the region, which isolated populations within subalpine forest refugia. The Northwestern Salamander (Ambystoma gracile) has a broad geographic distribution along the Pacific Coast from northern California to southern Alaska. The northern populations were previously known as A. g. decorticatum, characterized by green-yellow spots, reduced parotoid glands, and 4 compared to 3 phalanges in A. g. gracile. For a long time the distribution of A. g. decorticatum was described as being “above the 51st latitude line”; however, this fails to recognize that specimens resembling A. g. gracile also occur above this line, and that both subspecies co-occur in the Olympic Mountains in Washington. We will investigate the phylogenetic relationships among A. gracile populations with an emphasis on populations in the Olympic Mountains, where phenotypes match both the northern and southern subspecies. We aim to test whether these two subspecies are weakly differentiated populations that are separated by elevational and/or habitat differences, or if they are reproductively isolated. Using new field-collected and museum loaned specimens, we will sequence genomic data using double digest restriction-site associated sequencing (ddRADseq) as well as mitochondrial DNA (mtDNA). As climate change further encroaches on subalpine habitats, being able to properly understand the genetic diversity of this species is important in constructing reliable conservation measures for populations at different elevations.


    74.    SSAR Rabb  How do Ecomorphological Relationships Influence UV and Temperature Regulation? A Preliminary Study on Sceloporus occidentalis. Dylan Bryant*, Christopher Newport University; Dane Conley, Christopher Newport University; Matthew Lattanzio, Christopher Newport University   dylan.bryant.19@cnu.edu

    For wide-ranging lizards, ecomorphological variation can occur as members of a species interact with variation in available perch types, canopy and ground coverage across environments. Prior work suggests that these relationships should also impact thermoregulation, particularly with respect to their realized body temperatures. Moreover, lizards can also actively regulate their UV exposure. The extent that those relationships also influence UV exposure, and the extent that UV exposure and body temperatures match optimal values, remain unclear. Western fence lizards (Sceloporus occidentalis) naturally range from low-elevation coastal tree stands to mid-elevation mountainous and predominantly rocky habitats. Here we provide some preliminary insights into 1) the nature of the relationships between morphology, habitat use, body temperature, and UV exposure, and 2) how those relationships vary by sex and geographically, using data collected on N = 202 adult fence lizards across four localities in southwestern California that differ in habitat structure and elevation. Currently we are in the data analysis phase of this project. Based on prior findings we expect to observe 1) males larger than females, particularly those at lower elevations and those using more-open microhabitats, 2) a positive association between habitat openness and both temperature and UV exposure, and 3) evidence of a potential trade-off between competing UV and thermal demands. Specifically, lizards attempting to sustain optimal UV levels may need to expose themselves to higher-than-preferred temperatures. We anticipate our findings will provide some novel insights into the factors associated with ecological success in wide-ranging species.


    75.    SSAR Rabb  Characterizing the Abundance, Diversity, and Composition of Herpetofauna Communities in Contrasting Oregon White Oak (Quercus garryana) Habitats. Matthew Manus*, Western Oregon University; Ava Howard, Western Oregon University; Gareth Hopkins, Western Oregon University   mmanus18@mail.wou.edu

    Amphibians and reptiles (herpetofauna) require specific, yet different abiotic factors in their habitats to survive and reproduce. Herpetofauna are important yet highly understudied components of endangered Oregon white oak (Quercus garryana) ecosystems in the Pacific Northwest. This study focuses on characterizing the abundance, diversity, and composition of herpetofauna within four contrasting oak habitats in the Pacific Northwest: oak savannah, mixed deciduous-conifer forest, forest thinned to oak woodland and left unmanaged, and forest thinned to oak woodland and managed for an understory of grasses and native forbs. Herpetofauna surveys (cover objects, time-constrained searches, and incidental observations) were conducted 2019-22 at our 22-ha field site. Six different reptiles and three different amphibian species were found at the site, with differing communities in different habitat types. The greatest diversity of amphibians and reptiles was found in the restored and managed oak woodland. Reptiles were more likely to be found in habitats with less canopy coverage, while high canopy coverage was critical for amphibians. There was 5-6 times higher detection probability of reptiles in oak woodland with a managed understory and oak savannah compared to deciduous-conifer forest. Among forest thinned to oak woodland, detection probability was twice as high when the understory was managed. These data show that even within a small area, variation between habitats has great effects on herpetofauna communities, and that active restoration may be an effective tool for conservation. Characterizing herpetofauna communities in a variety of oak habitats will aide landowners in making long-term management decisions in this endangered ecosystem.




    76.    SSAR Rabb  Effects of Habitat Alteration and Co-Occurrence With Introduced Red-Eared Sliders on Southwestern Pond Turtle Basking Site Usage. Michael Skibsted*, Santa Margarita Catholic High School; Greg Pauly, Natural History Museum of Los Angeles County   skibstedm@gmail.com

    Species inhabiting urban waterways face numerous threats including water pollution, invasive species, and habitat alteration. While virtually all water bodies are at risk of significant human modification, urban waterways are subject to a unique set of human modification practices to reduce flood risk. The vast amount of impervious surface in urbanized areas can dramatically increase storm runoff and the risk of catastrophic flooding. As a result, management agencies often implement flood and erosion control measures such as creation of drop structures, riprapping, deadwood removal, and manual modification to streamline watercourses and expedite the flow of water away from urban areas. These efforts can reduce the habitat quality for native species. We conducted 32 days of surveys over the course of approximately six months investigating basking behavior and basking substrate usage by native Southwestern Pond Turtles (Emys pallida) and non-native Red-Eared Sliders (Trachemys scripta elegans) in an urban creek in Orange County, California. We compare usage of basking site substrates between these two species. Noise level, another factor associated with urban areas, is also analyzed. Results are interpreted in context of urban stream management, and the effects both heavy human modification of a creek system and introduced species can have individually, and together, on Southwestern Pond Turtles in an urban creek. We also recommend management practices that would benefit declining Southwestern Pond Turtles based on the results obtained herein.


    77.    SSAR Rabb  Looking at Morphological Variations in Blue-banded Sea Kraits, Laticauda Laticaudata. Laura Lewis*, Auburn University; Jamie Oaks, Auburn University; Matthew Buehler, Auburn Univerrsity   ljlewis125@gmail.com

    Laticauda laticaudata, or the blue-banded sea krait, is a semi-marine adapted elapid species. Its distribution spans from Myanmar, east to the Melanesian island of Niue, and north to the Ryukyu Islands of Japan. A recent phylogenetic study based on a multi-locus dataset has found a deep divergence between western Pacific and Melanesian populations of L. laticaudata, suggesting that L. muelleri be elevated from the synonymy of L. laticaudata to describe blue-banded sea kraits from Melanesia. To identify species boundaries using an integrative approach, we have gathered a morphological dataset to test for patterns of morphological variation that correspond with genetic divergences to aid in delimiting these two species. This is the first study to systematically explore the morphological diversity of the blue banded sea kraits.


    78.    SSAR Rabb  Exposure to silver nanoparticles and the negative effects on the weight and growth of Ambystoma mexicanum (Axolotls). Samantha Fike*, Lock Haven University; Kristen Cherry, Lock Haven University; Ashley Mallory, Lock Haven University; Kyle Root, Lock Haven University; Jennifer Deitloff, Lock Haven University   jenneymd@gmail.com

    The effects of Silver Nanoparticles (AgNPs) on natural ecosystems and individual organisms are widely unknown. Few studies have examined the effects of AgNPs, and results can be conflicting. Viability of amphibians, in general, can be used as indicators of environment health due to their sensitivity to environmental conditions. Axolotls (Ambystoma mexicanum) are paedomorphic, aquatic salamanders that are often used in toxicity studies. We conducted an experiment that tested the effects of AgNPs on growth and development of axolotls. During this experiment, we exposed axolotls to three different concentrations of AgNPs (and included a control group) through dissolving AgNPs in the water where they were kept. We regularly changed their water so it remained clean and so that AgNPs would remain suspended in their treatment water. Axolotls were also fed brine shrimp three times weekly. We recorded the weight of each axolotl weekly. Our research suggests that AgNP exposure has negative effects on weight of axolotls. Individuals exposed to high concentration of nanoparticles did not gain weight, or gained weight more slowly that individuals exposed to lower levels and from the control group. Our research supports the idea that exposure to AgNPs can have a negative effect on living organisms. There are many areas in which these research questions should be expanded so that we can gain a better understanding of how nanoparticles affect natural environments.


    79.    SSAR Rabb  Exposure to silver nanoparticles negatively affects growth and survival of Ambystoma mexicanum (Axolotls). Kristen Cherry*, Lock Haven University; Samantha Fike, Lock Haven University; Ashley Mallory, Lock Haven University; Kyle Root, Lock Haven University; Jennifer Deitloff, Lock Haven University   jenneymd@gmail.com

    Silver nanoparticles (AgNPs) contain many antimicrobial properties and are most often used in waste-water treatment. The environmental impacts of AgNPs on biological systems are widely unknown because few studies have examined them, and these do not demonstrate consistency when comparing the results. Amphibian viability often reveals the quality of the environment in nature due to their increased sensitivity to toxins. With this study, we examined whether length and mortality rates of axolotls (Ambystoma mexicanum) were affected by prolonged silver nanoparticle exposure. We predicted that the growth of axolotls would be hindered, and that the axolotl morality rates would increase in response to AgNP exposure. We conducted an eight-week experiment and a six-week experiment at Lock Haven University of Pennsylvania to evaluate growth and mortality of axolotls when exposed to various concentrations of silver nanoparticles. The AgNP concentration groups included a control, and low, medium, and high concentrations. Axolotl length was recorded by photographing axolotls weekly and measuring length from the photographs using TpsDig. Axolotl mortality for each concentration group was also recorded. Preliminary findings suggest that greater concentrations of AgNPs resulted in decreased length values and increased mortality rates. This research suggests that exposure to silver nanoparticles has negative developmental consequences for axolotls and adds support to the idea that nanoparticles can have detrimental effects in natural environments.


    80.  A Complicated Answer to a Complicated Problem: Phylogeography of the Pachydactylus serval/weberigroup and the status of P. montanus onscepensis. Matthew Buehler*, Auburn University; Jamie R. Oaks, Auburn University; Todd R. Jackman, Villanova University; Aaron M. Bauer, Villanova University   mbuehle3@gmail.com

    Pachydactylus is the most speciose genus of gecko endemic to sub-Saharan Africa with 56 described species. Within the genus, the serval/weberi species group includes 20 species from southwestern Africa, many of which occur in the Orange River Valley or the adjacent ?Ai-?Ais/Richtersveld Transfrontier Park. We present the most complete phylogeographic study of the species group using a molecular dataset that contains samples from all members of the serval/weberi species group. We sequenced a single mitochondrial locus (ND2) and three nuclear loci (Rag-1, MXRA5, and KIF24) for phylogenetic analyses and species delimitation. In addition to estimating the evolutionary history of the species group, we also assessed whether P. montanus onscepensis,a taxon putatively endemic to a small stretch of the Orange River, represents a unique evolutionary lineage warranting elevation to full species status. Previous phylogenetic studies used a single mitochondrial locus and found that P. m. onscepensis is divergent and sister to all other P. montanus, however, more data were needed to verify its specific status. Our results suggest that P. m. onscepensis does represent a unique evolutionary lineage, and that there may have been a historic hybridization event between P. m. onscepensis and other sympatric lineages of Pachydactylus, such P. carinatus.


    81.    SSAR Hutchison Evolution, Genetics, Systematics, Physiology, & Morphology   Genomic analyses and a common garden rearing experiment bring new insights into the relationship between two sister Ambystoma salamanders. Victor Fitzgerald*, Miami University; Jason Bracken, Miami University; Tereza Jezkova, Miami University   fitzgev@miamioh.edu

    Ambystoma barbouri and A. texanum are considered two separate, closely related salamander species. The defining feature of these salamanders are traits associated with their breeding behavior. Ambystoma barbouri is generally a stream breeding salamander, which attaches its eggs in a single layer underneath flat rocks. Ambystoma texanum is generally a vernal pool breeder which deposits eggs in small clumps on submerged vegetation. These differences in reproductive traits together with deep mitochondrial DNA divergence found within these two salamanders have been used to delineate the two species. However, the distribution of mtDNA lineages and reproductive traits is not congruent and genetic and observational studies show evidence of hybridization between the two species. Here, we use ddRAD sequencing and a common garden rearing experiment to explore genetic differences between the two species. Our genomic analysis of A. barbouri and A. texanum sampled across Ohio, Indiana, and Kentucky revealed three, extensively introgressing, genetic groups, which do not support the delimitation of the species. Our experiment revealed that the females of each species retain their distinct reproductive traits under a common treatment and their larvae show differences in hatch time, hatch size, size at metamorphosis, time to metamorphosis, and pigmentation. The two species readily hybridized, hybrid larvae did not show an apparent reduction in fitness (as measured by hatching and metamorphosis rate), and the hybrid larvae showed an apparent maternal effect. We conclude that the two species do not form two monophyletic lineages but do exhibit phenotypic differences that signal presence of local adaptation.


    82.    SSAR Hutchison Evolution, Genetics, Systematics, Physiology, & Morphology   Transferability of Assisted Reproductive Techniques (ART) from Model Anurans to Target Species. Namia Stevenson*, Mississippi State University; Isabella Burger, Mississippi State University; Dustin Smith, North Carolina Zoo; Carrie Kouba, Mississippi State University; Andy Kouba, Mississippi State University   namiastevenson@gmail.com

    Application of assisted reproductive technologies (ART) for ex-situ populations of threatened anurans failing to reproduce naturally is imperative for population sustainability and genetic management. Due to the large number of imperiled anurans, determining the level of ART protocol transferability between groups is vital to ensuring breeding success of these captive amphibian colonies, since developing one protocol per species is unlikely. We hypothesize that the hormone protocols developed in model species will successfully induce gametogenesis in three target species of conservation concern. Exogenous hormone treatments were administered to stimulate spermiation in male Pseudacris ornata (n=1), Incilius alvarius (n=3), and Lithobates capito (n=2) or oviposition in female I. alvarius (n=1) and L. capito (n=3). The P. ornata responded to the hormone treatment and produced an average motility of 74.5%. Sixty-six percent of I. alvarius males responded to the hormone treatment and produced an average motility of 46%. Sperm was then used for in-vitro fertilization (IVF) of eggs collected by the I. alvarius female, producing 12 tadpoles. For L. capito, 50% of males responded to the hormone treatment producing an average motility of 66.2% and 100% of the females responded to the hormones; IVF resulted in 149 tadpoles. These results support the hypothesis that ART protocols can be transferred between species, successfully inducing gametogenesis and producing offspring. The transferability of hormone protocols to three new species highlights the applicability of these tools for species in decline that may need future conservation intervention.


    83.    SSAR Hutchison Evolution, Genetics, Systematics, Physiology, & Morphology   Tympanic Middle Ear Loss and Skull Morphology in African Dwarf Toads of the genera Poyntonophrynus, Mertensophryne, and Capensibufo. Claire Tracy*, Villanova University; David Blackburn, University of Florida; Edward Stanley, University of Florida; Todd Jackman, Villanova University; Aaron Bauer, Villanova University   claire5060@gmail.com

    African dwarf toads of the genera Poyntonophrynus, Mertensophryne, and Capensibufo are closely related genera that are found across southern Africa in arid and semi-arid environments. Recent work has shown that all three genera have both eared and earless species. While these toads share the loss of the tympanic middle ear (TME) in some but not all species, relatively little detail is known about their ecology and life history. Loss of the TME has been shown to be labile across the anuran tree of life, however no study to date has incorporated variation within Poyntonophrynus and Mertensophryne into their study of TME evolution. In this study we used CT scans to isolate the skulls of each species within Mertensophryne, Poyntonophrynus, and Capensibufo. We found that the loss of the tympanic middle ear in these genera is not a form of paedomorphosis, supporting previous findings that loss of the TME is labile in anurans. We additionally found skeletal evidence supporting paedomorphosis in some species, and find that paedomorphosis in these species does not necessitate loss of the TME. Finally, we provide a skeletal comparison of the three genera.


    85.    SSAR Hutchison Ecology, Natural History, Distribution, & Behavior  The Impact of Development on Copperheads in Connecticut: A Preliminary Study. Andrew Powers*, Western Connecticut State University; Theodora Pinou, Western Connecticut State University   powers077@wcsu.edu

    The eastern copperhead (Agkistrodon contortrix) is a medium-sized viper native to the east coast of the United States of America. However, within New England, the copperhead has experienced declines within this range and is considered a sensitive species in Connecticut. The main cause of this decline is thought to be a combination of human persecution and habitat loss. Within the last three decades there has been an increase in urbanization and land-use change in central Connecticut. The effect of land-use change on snakes is not fully studied. Previous research has found that southern copperheads in urban sites are significantly smaller than those in rural sites (Carrasco-Harris et al. 2020). Our preliminary study examines the effects of habitat fragmentation on copperhead body size by comparing snout-vent length of snakes sampled at two fragmented sites and a larger unfragmented site. By understanding how development is impacting copperheads in their central Connecticut stronghold, this sensitive species can better be preserved at the northeastern edge of their range.


    87.    SSAR Hutchison Ecology, Natural History, Distribution, & Behavior  Thermal ecology of desert-living tortoises. Julia Joos*, Ohio University; Donald B. Miles, Ohio University   jj064318@ohio.edu

    Almost 50% of modern tortoise species are endangered or already extinct. The compact body plan of tortoises favors heat conservation compared to other terrestrial ectotherm vertebrates, which might pose an increased risk of overheating. Desert-dwelling tortoises dig burrows or seek refuge in rock crevices, shade to avoid the heat. However, tortoise habitat in arid environments of North America is increasing in temperature and prolonged drought reducing available habitat due to climate change. There are six tortoise species in North America and Mexico (genus Gopherus) and they differ in distribution, morphology, body size, diet, habitat, and shelter site selection. Most Gopherus species are assumed to have a similar physiology as G. agassiziialthough there are differences in genetics and ecology and more recent evidence suggesting varying thermoregulatory strategies for different species. Therefore, understanding each species’ specific habitat requirements and physiological properties are important to direct conservation practices and allow inferences about tortoises’ potential to cope with temperature shifts and habitat alterations induced by climate change. Whereas niche modeling predicts extensive range contractions for many chelonian species, there is a lack of sufficient physiological data at an appropriate resolution of microhabitats to refine these models and improve predictions to guide conservation action for specific populations and species. Our study measures core physiological data, operative environmental temperatures, and movement and activity patterns of species occupying habitats differing in vegetation composition and structure: G. flavomarginatus, G. morafkai, and G. evgoodei in the Southwestern US and Mexico.


    88.    SSAR Hutchison Ecology, Natural History, Distribution, & Behavior  Northeast Texas Anuran Composition in an Urban-Rural Gradient . Andrew Savage*, Texas A&M University - Commerce; Derald Harp, Texas A&M University - Commerce; Johanna Delgado - Acevedo, Texas A&M University - Commerce   andsavage1997@gmail.com

    Amphibians are a vulnerable group that has been in decline for decades. Many ectotherms including anurans are affected by the environment around them. In a comfortable temperature, anurans can be found to be active. The presence of urban heat islands could have an effect on anuran populations present. We have been capturing anuran species at 3 different locations using drift fences and pitfall and funnel traps. Captured specimens are measured by their snout-to-vent length (SVL). A record of both temperature and humidity is taken every 10 minutes with a data logger kept at each site. Night call surveys are conducted once a week between 22:00 and 02:30 with each survey being given a rank between 0 and 4 to quantify activity. A total of 10 species have been captured between the three sites. The average SVL decreases in the more urban sites with a .36 cm difference between the most rural site and most urban. Nocturnal calling activity has been highest between the times of 23:30 and 00:59 both in average call level and occurrence. The site with the most might time activity in both call level and frequency is our sub-urban site. When activity is influenced by environmental conditions, changes in these conditions can lead to the differences between population activity. These changes could create rifts between populations on a temporal scale. Environmental conditions influence anuran activity and understanding the degree of influence is important to anuran conservation as towns and cities grow and climate change progresses.


    89.    SSAR Hutchison Ecology, Natural History, Distribution, & Behavior  Characterizing Plethodontid Salamander Communities across an Urban Gradient using eDNA. Leah Rittenburg*, Kennesaw State University; Todd Pierson, Kennesaw State University   lrittenb@students.kennesaw.edu

    Urban sprawl in the southeast United States is projected to more than double by 2060, jeopardizing many ecosystems. Particularly at risk are river and stream systems, as urban factors upstream can have far reaching effects within the stream. Urban streams often see decreases in native species diversity, including local extirpations of many plethodontid salamander species. However, few studies have characterized salamander communities across an urban gradient. One relatively new alternative to traditional community composition surveys uses environmental DNA (eDNA), the DNA left behind in the environment by organisms, to determine species presence. Using eDNA offers a faster and less disruptive method of sampling, but requires researchers to extract, amplify, and sequence DNA in the lab. In order to characterize plethodontid salamanders across an urban gradient, we collected eDNA from 25 sites in Atlanta, GA, USA ranging in level of habitat degradation. We targeted the 12S region of the mitochondrial genome and uniquely indexed all of our samples using iTru primers. We then compared the resulting sequences to a reference database to characterize plethodontid salamanders present at each site. Using a standardized metric of urbanization, we evaluated changes in salamander community composition across an urban gradient, expanding our understanding of how these amphibians respond to increased urbanization.


    90.    SSAR Hutchison Ecology, Natural History, Distribution, & Behavior  Transmission of Batrachochytrium dendrobatidis in Terrestrial-Breeding Frogs in Andean Montane Forests. Jonathan M Adamski*, Florida international University; Hamlet J Maza Camacho, Universidad Nacional San Antonio Abad del Cusco; James W Ttito Nina, Universidad Nacional San Antonio Abad del Cusco; M Isabel Diaz Huaman, Universidad Nacional San Antonio Abad del Cusco; Alessandro Catenazzi, Florida international University   jonathan.m.adamski@gmail.com

    The fungal pathogen Batrachochytrium dendrobatidis (Bd) has been responsible for the decline and extinction of numerous frog species around the world. This disease is transmitted through aquatic environments and attacks the skin of its host species. The Andes of South America are one of the most biodiverse regions, and its frog communities have declined sharply with the spread of Bd. Utilizing mark and recapture methods, we are examining Bd/host dynamics in frogs that do not require aquatic environments to complete their life cycle (i.e., terrestrial breeding frogs). The susceptibility of several of the study species has previously been assessed in laboratory infection trials, but we ignore how infection affects hosts in the wild, and the community level responses to enzootic conditions. We have completed the first year surveying fifteen frog species along twelve 100 m long transects. We captured 1024 frogs, 24% of which have been recaptured at least once, including 100 long term recaptures (frogs recaptured at least once at intervals of at least two weeks). Among long term recaptures, 26% became infected, 7% stayed infected, 52% stayed uninfected, and 14% cleared infection, demonstrating that frogs can clear infection in the wild. Prevalence of infection is 21% (95% CI [17.9%, 23.8%]) and preliminary data suggest that prevalence correlates with transect host density. Data on movements, infection history, changes in spatial distribution and abundance will inform models on disease dynamics, with the hope of increasing our understanding of how a water-dependent fungus can spread among terrestrial organisms.


    91.    SSAR Hutchison Ecology, Natural History, Distribution, & Behavior  Responses of Lesser Sirens (Caudata: Sirenidae) to Chemosensory Cues. Mackenzie Hanna*, Arkansas State University; Stephen Mullin, Arkansas State University   mackenzi.hanna@smail.astate.edu

    Wetland ecosystems contain a high level of biodiversity, which is typically reflected in a complex trophic structure. Lesser Sirens (Siren intermedia) are aquatic salamanders that inhabit permanent and semi-permanent bodies of water throughout all life-history stages. Sirens have a rapid growth rate, and can occur at high densities within an ecosystem, suggesting that they play key roles in the trophic structures of wetlands. Although a basic understanding of their diet exists, the preferred prey type of sirens remains unknown. We conducted experimental trials on adult and juvenile sirens collected in northeast Arkansas to determine the prey preference of this species. We presented individual subjects with swabs, each saturated with chemical cues extracted from earthworms (Lumbricus sp.), crayfish (Procambrus sp.), tadpoles (Lithobates sp.), or control odors. We observed the behavioral reactions of each subject to the different scents, and recorded both latency to touch the swab and any occurrence of biting behavior. In those trials where the subject bit the swab, we scaled the latency value to account for increased predatory interest in the chemical cue. We discuss our results with respect to our future research directions and, more generally, an increased understanding of the role of sirens in wetland ecosystems.


    92.    SSAR Hutchison Conservation & Management  Size and Temperature Affect Detection of Cryptic Herpetofauna by Camera Traps. Ally Brown*, University of Georgia; Devyn Hannon, University of Georgia; Natalie Schliekelman, Clarke Central High School; John Maerz, University of Georgia   a98brown@gmail.com

    Herpetofauna are notoriously difficult taxa to survey. Camera trapping has been proposed as a method for conducting inventories of these cryptic species; however, estimates of detection rates and factors impacting detection are lacking. The goal of this study was to explore the effect of body size and temperature on detection of snakes and frogs by different models of passive infrared (PIR) camera traps. We hypothesized that detection would be positively correlated with size of the individual and the temperature differential between the individual and the substrate. Using 10 wildlife camera models mounted to the underside of a 5-gallon bucket, we performed 500 trials on 5 snake species. The top models were the Browning Dark Ops, Mossy Oak Covert Scouting Camera, and Reconyx HyperFire 2. We selected Covert as our target model and conducted an additional 72 trials using 6 Gopher frogs (Rana capito). Absolute temperature differential was strongly, positively correlated with detection of Gopher frogs. Snakes that were 1 degree Celsius warmer than the substrate had a 13% higher detection rate than snakes that were 1 degree cooler than the substrate. Detection also increased 7% per 100-gram increase in snake mass; however, Gopher frog mass had no measurable effect on detection. We conclude that detection of herpetofauna by PIR cameras depends on species and individual-specific characteristics, namely body size, and can be strongly influenced by an animal's temperature. For this reason, PIR cameras may be most effective at detecting larger, diurnal herpetofauna and least effective at detecting smaller, nocturnal species.


    93.    SSAR Hutchison Conservation & Management  Human-Snake Conflict Mitigation: Policies for Relocating Nuisance Snakes in the U.S. Robin Bedard*, California Polytechnic State University; Alex Goode, California Polytechnic State University; Tess McIntyre, California Polytechnic State University; Maddy Martin, California Polytechnic State University; Megan Rottenborg, California Polytechnic State University; Emily Taylor, California Polytechnic State University   rbedard@calpoly.edu

    In recent years, relocation of nuisance snakes has become a widespread practice in the United States, aided by social media pages connecting people to volunteer and for-profit snake relocators. However, this has led to a growing disconnect between the individuals performing the relocations and the state wildlife agencies responsible for the policies, permitting, and training regarding nuisance snake management. Misinformation about permitting or training required for snake relocation abounds, and most relocators are unsure about requirements and often struggle to find relevant information and resources from the wildlife agencies responsible for policies. Additionally, many relocators use procedures that intentionally or unintentionally disregard the health and survival of the snakes and are instead intended only to mitigate human-wildlife conflict. To bridge this disconnect, we conducted a study to obtain data on policies, permitting, and training from the sole wildlife official responsible for nuisance snake relocations in each U.S. continental state. We compared the policies gathered from these officials with data on actual procedures being performed by snake relocators that we uncovered with another survey, including the relocators’ understanding of required permits, training, and best practices (e.g., how far to relocate snakes and other items). The final product of this study will be a database connecting relocators with policies and best practice information to assist them in conducting relocations legally, safely, and in the best interest of the snakes. This project will mitigate human-wildlife conflict by benefitting everyone involved, including the wildlife agencies, snake relocators, and the snakes being relocated.


    94.    SSAR Hutchison Conservation & Management  Generalist fungal pathogens: Experimental confirmation that Ophidiomyces ophiodiicolaand Nannizziopsis guarroiare not as host specific as previously thought. Savannah Gentry*, University of Wisconsin-Madison; Jeffrey Lorch, U.S. Geological Survey – National Wildlife Health Center; Julia Lankton, U.S. Geological Survey – National Wildlife Health Center; Anne Pringle, University of Wisconsin-Madison   sgentry@wisc.edu

    Recent, multiple emergences of devastating fungal diseases of wildlife have caused concerns for conservation: white nose syndrome in bats, chytridiomycosis in amphibians, and snake fungal disease in snakes. Identifying a fungal pathogen’s host range is critical to understanding disease ecology and impacts. Ophidiomyces ophiodiicola, the causative agent of snake fungal disease, and Nannizziopsis guarroi, the causative agent of yellow fungal disease in lizards, were formerly classified as a single species (Chrysosporium anamorph of the Nannizziopsis vriesii) but are now recognized as distinct species capable of affecting different hosts. Motivated in part by the conservation concern of disease spillover from captive to wild, naïve populations, we designed an experiment to determine whether O. ophiodiicola and N. guarroi could cross-infect different hosts. We conducted a 52-day challenge experiment with corn snakes (Pantherophis guttatus) and central bearded dragons (Pogona vitticeps), inoculating groups of each species with O. ophiodiicola and N. guarroi. Clinical and histopathological signs of infection, along with re-isolation of the pathogen, confirmed that both fungi were capable of causing infection in snakes and lizards. Our results demonstrate thatO. ophiodiicola and N. guarroi have a broader host range among reptiles than previously thought, and that future pathogen screening should focus on a diversity of reptile species.


    95.    SSAR Hutchison Conservation & Management  Predicting the Distribution of Soil Microbes Associated with Snake Fungal Disease in Arkansas. Natalie Haydt*, Arkansas State University; Emily Bellis, Arkansas State University; Lori Neuman-Lee, Arkansas State University   natalie.haydt@smail.astate.edu

    Over the past two decades, snake fungal disease (SFD) has emerged as a threat to North American snake populations. To prioritize management of threatened species, managers need to know which habitats are more vulnerable to the causative fungus Ophidiomyces ophiodiicola. This is especially important in states with no published reports of SFD, such as Arkansas. Habitat susceptibility to O. ophiodiicola is influenced by environmental microbial communities which can facilitate or suppress the establishment of O. ophiodiicola. Delimiting the distribution of relevant microbes is vital to prioritizing SFD management areas. We developed a joint species distribution model to predict distributions of microbial genera known to facilitate O. ophiodiicola and projected our model to Arkansas. In the absence of fine-scale occurrence data for O. ophiodiicola, we trained our model using global soil microbiome datasets to identify abiotic environments that might be particularly likely to harbor O. ophiodiicola-associated microbial communities and thus pose higher SFD risk. Our model predicts the occurrence probability of O. ophiodiicola-associated microbial genera in Arkansas given predictors characterizing habitat type, habitat disturbance, soil, and climate. Preliminary presence and absence data for O. ophiodiicola detection in Arkansas for soil samples collected in spring and summer of 2022 were used to test model predictions. The final model serves as a management tool to predict habitats in which snakes are more likely to come into contact with microbial communities positively associated with occurrence of O. ophiodiicola. Predictions from our model can inform areas chosen for further study of SFD in Arkansas.


    97.    SSAR Hutchison Conservation & Management  An update on a threatened anuran (Acris blanchardi) in Michigan: persistence and its relationship with landcover. Travis Rainey*, Central Michigan University   travrain06@gmail.com

    Blanchard’s Cricket Frog (Acris blanchardi) is a warty, small (1.6-3.5cm snout-vent length), nonclimbing, wide-ranging treefrog found throughout the central United States. It has been well documented that A. blanchardi populations are declining across their northern and western range since at least the 1970s. While local extinctions in Michigan have been reported, there is no statewide, species-specific monitoring program, nor is the current distribution well understood. To address the unknown status of the A. blanchardi range in Michigan, nocturnal call surveys were conducted across all georeferenced historic records, which span the southern Lower Peninsula. Additionally, to understand how landcover and land use types might affect the species persistence at these sites, the proportions of various landcover categories within buffers of extant and extirpated sites were compared. Results confirm the species is continuing to decline in Michigan, even over the last two decades. Agricultural, barren and herbaceous landcovers could facilitate persistence, while developed and forested landcovers could impede persistence; therefore anthropogenic landcover changes could facilitate (e.g. crops) or hinder (e.g. development) persistence.


    98.    SSAR Hutchison Conservation & Management  Headstarting Efforts for the Endangered Carolina Gopher Frog (Lithobates capito) Resulting in Developmental Abnormalities: Comparison of Water Quality & Microbial Communities. Kiersten Nelson*, Savannah River Ecology Laboratory, University of Georgia; Raven Bier, Savannah River Ecology Laboratory, University of Georgia; Scott Weir, Department of Biology and Chemistry, Queens University of Charlotte; Adam McFall, Savannah River Ecology Laboratory, University of Georgia; E. Tucker Stonecypher, Savannah River Ecology Laboratory, University of Georgia; Christian Swartzbaugh, Savannah River Ecology Laboratory, University of Georgia; Stacey Lance, Savannah River Ecology Laboratory, University of Georgia   k.nelson@uga.edu

    Headstarting to augment Carolina gopher frog (Lithobates capito) populations may be critical for population viability, however, current methods are occasionally resulting in juveniles with developmental abnormalities from an unknown cause. There are nine headstarting facilities across three states that are rearing gopher frogs. Since 2017, developmental abnormalities have been reported in low frequencies and prevalence is increasing. In 2021, our lab at the University of Georgia Savannah River Ecology Lab, reared gopher frogs that resulted in nearly 100% emerging with developmental abnormalities. To begin addressing the causes, we worked with seven facilities to collect water samples from tanks that did, and did not, result in abnormal gopher frogs. Additionally, we ruled out other common causes of abnormalities such as pathogens and toxins. Here, we investigate the potential role of water quality and/or microbial communities by analyzing water samples collected from headstarting tanks from seven facilities that varied in the proportion and severity of abnormal frogs. Water chemistry varied widely across headstarting tanks within and across facilities. For example, calcium and copper concentrations ranged from 0.38 to 42.94 ppm and 0.56 to 17.95 ppb respectively. Using a metabarcoding approach, we characterized the microbial communities and identified over 75 known classes of Eukarya, Archaea, and Bacteria. Proportions of cyanobacteria, some of which can secrete teratogenic retinoids, ranged from 0% to 37%. We discuss these results with respect to presence absence of abnormalities across tanks and severity within tanks.


    99.    SSAR Hutchison Conservation & Management  Effects of Vegetation and Historical Land Use on the Occurrence of Endemic Anurans. Anna Humphrey*, Marshall University; Jayme Waldron, Marshall University; April Atkinson, SCDNR; Jay Cantrell, SCDNR; Will Dillman, SCDNR; Shane Welch, Marshall University   amhumph2@ncsu.edu

    Historical degradation of the longleaf pine (Pinus palustris) ecosystem (LPE)—and the minimal legal protections afforded to seasonal wetlands—resulted in the alteration or loss of many isolated wetlands in the southern US. Efforts to restore and conserve LPE wetlands have been underway for decades to promote the high faunal and floral diversity they support. Most wetland restoration and conservation efforts within the LPE focus on vegetative responses to guide management protocols (e.g., hardwood basal area reduction, prescribed fire), assuming animals will respond to restoration by redistributing across landscapes to occupy the most suitable habitat patches. However, the distributions of many amphibians reflect land use legacies, suggesting some species are either unable to redistribute across landscapes or those distributional responses can have significant lags. We examined the potential interaction between current restoration efforts and land use legacies using the occurrence of LPE-endemic anurans at 35 independent, isolated wetlands in the South Carolina Coastal Plain. We used anuran chorus data collected using autonomous recording units to assess anuran presence relative to a range of covariates indicative of habitat disturbances and current vegetative structure. We used historical aerial photographs to assess habitat disturbances from historical land use (e.g., agriculture, intensive silviculture) and wetland modification (e.g., ditching), and quantified the level of disturbance to create ordinal covariates. Anuran chorus data indicated prior land use and wetland modification influenced the occurrence of endemic species, suggesting land use legacies can interact with modern management strategies and affect restoration outcomes.


    100.    SSAR Hutchison Conservation & Management  Distribution Predicts Global Patterns of Extinction Risk in Toads. Desi Wilson*, Purdue University; Ana Ospina, Purdue University; Nigel Brown, Brown University; Ximena Bernal, Purdue University   desi.wilson@okstate.edu

    Among vertebrates, amphibians are the most vulnerable group to extinction as novel selective agents, like disease and habitat degradation, have resulted in increased mortality. Despite the worldwide population decline of amphibians, there is substantial variation between species in their extinction risk. Given that the main threats to amphibians, especially anurans, vary in predictably with latitude and altitude across the world, anuran species are expected to differ in extinction risk along those geographic axes. We examined this prediction in Bufonidae (toads), a large anuran family with a worldwide distribution and variation in their extinction risk. This was done using distribution and conservation status data for 458 species of toads from the International Union for Conservation of Nature Red List assessment. We characterized the latitudinal and altitudinal distribution for each species and determined toad species richness along those spatial axes. Using phylogenetic analysis, we evaluated how distribution affects extinction risk in toads worldwide. We found that species distribution is a strong predictor of their extinction risk. Overall, species that occur at low latitudes and high altitudes are more likely to have a high risk of extinction. These findings highlight the conservation challenge in this clade as our results also revealed that low latitudes hold the highest toad diversity and high altitudes have a high proportion of endemic species. We also found that species that share evolutionary history exhibit similar extinction risk. This study displays predictors of extinction risk that offer insights for developing and targeting conservation strategies given limited species assessment information.


    101.    ASIH Contributed   The Future of ASIH: An open discussion and listening space. Emily Taylor*, California Polytechnic State University; Prosanta Chakrabarty*, Louisiana State University   prosanta@lsu.edu

    This poster is meant to invite an open discussion about the role of ASIH leadership in working towards meaningful goals for change and strengthening areas that we already do well. We can also discuss the future of ichthyology and herpetology generally (genomics, MRI/CT scanning), diversity and student issues, or anything you might want to bring up with the President, President-Elect, and other members of ASIH leadership.


    102.    Contributed Herpetology  The effects of food web complexity and phenological variability on pond-breeding salamanders. Jon Davenport*, Appalachian State University; David Burton, Appalachian State University; Thomas Anderson, Southern Illinois University; Elyssa Winterton, Appalachian State University; Elyssa Winterton, Appalachian State University   davenportjm@appstate.edu

    Variability in phenological shifts (seasonal changes in biological events) has become more common with climate change. As phenological variability increases due to climatic factors, species interactions within communities can be affected. Shifts in hatching phenology can lead to body size variability within a population resulting in more complex food webs. Indeed, larval ambystomatid salamanders are common in many wetland communities and can be top predators, dependent on size-structure of populations. To understand the effects of shifting hatching phenology, we conducted a mesocosm experiment manipulating hatching synchrony of Ambystoma maculatum across three dates and food web complexity (presence of Ambystoma opacum, paedomorphic Ambystoma talpoideum, both present, neither present). We hypothesized that predation on A. maculatum would be highest in the lowest synchrony treatment due to predator satiation effects in high synchrony additions. We also predicted that A. talpoideum (top predator) would impose greater predation than A. opacum (intermediate predator) on A. maculatum. Food webs with A. talpoideum present had the lowest survival rates for A. maculatum compared to other food webs. A. maculatumsize at metamorphosis was also highest in the A. talpoideum food webs suggesting a thinning effect. Hatching synchrony treatments did not have a significant impact on survival or size at metamorphosis of A. maculatum except in treatments where intermediate and top predators were absent. Overall, our results show that top-down effects of predators may be enough to suppress the influence of phenological shifts but if unchecked can alter food webs.




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