Session 24: Lightning Talks IIRoom: Room 206D2022-07-29 10:00 - 12:00 |
| Moderator: Alicia Mathis |
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1. Predictors of Genomic Diversity within North American Squamates. Ivy Larkin, The Ohio State University; Edward A. Myers, Clemson University; Bryan C. Carstens, The Ohio State University; Lisa N. Barrow*, Museum of Southwestern Biology, University of New Mexico lisabarrow01@gmail.com
Comparisons of intraspecific genetic diversity across species can reveal the roles of geography, ecology, and life history in shaping biodiversity. The wide availability of mitochondrial DNA (mtDNA) sequences in open-access databases makes this marker practical for conducting analyses across several species in a common framework, but patterns may not be representative of overall species diversity. Here, we gather new and existing mtDNA sequences and genome-wide nuclear data (genotyping-by-sequencing; GBS) for 30 species of North American squamates sampled in the Southeastern and Southwestern United States. We estimated mtDNA nucleotide diversity for two mtDNA genes, COI (24 species alignments; average 16 sequences) and cytb (22 species; average 76 sequences), as well as nuclear heterozygosity and nucleotide diversity from GBS data for 119 individuals (30 species; four individuals and 6,820–44,309 loci per species). We show that nuclear genomic diversity estimates are highly consistent across individuals for some species, while other species show large differences, depending on the locality sampled. Mitochondrial and nuclear diversity estimates were not correlated within species, although sampling differences in the availability of data made these datasets difficult to compare. Range size was positively correlated with both cytb diversity (phylogenetically independent contrasts: R2 = 0.21, p = 0.03) and GBS diversity (R2 = 0.19; p = 0.02), while other predictors differed between the top models for each dataset. As new genome-wide datasets continue to be generated, mtDNA and nuclear diversity within species should be investigated to determine the predictors of diversity across a variety of taxonomic groups. |
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2. Using Genetic Forensics to Identify Shark Species Involved in Human Bites. Tyler Bowling*, University of Florida; Gavin Naylor, University of Florida; Lei Yang, University of Florida tylerbowling1993@hotmail.com
For decades physical wound characteristics have been used to identify shark species involved in human shark interactions. However, bite marks often lack significant definition, or species tooth morphology may be too similar to differentiate. Recent analysis has accurately identified species using residual DNA from objects bitten during encounters. However, most human shark interactions involve the person sustaining physical lacerations with high contamination from human DNA. Using specifically designed primers, we amplified only shark DNA from swabbed bite wounds. These primers amplify short fragments (300-700bp) of 13 carcharhiniform sharks and three lamniform sharks frequently implicated in bites on humans. These precise segments allow for easier PCR amplification and DNA sequencing when using low-quality template DNA. At the “shark bite capital of the world,” New Smyrna Beach (NSB), Florida, we have collaborated with the county beach patrol to collect swabs of victim wounds immediately after a bite. We have collected seven swabs, three of which have been identified by our amplification technique as Carcharhinus limbatus, with two more likely C. limbatus. Because of the high frequency of bites at NSB, we are conducting a movement ecology study focusing on local shark bite causes and prevention. Accurate species identifications from swabbing have informed local tagging priorities. This work is ongoing and further calibration is needed. Initial results suggest that this technique could be widely used in shark bite species identification. With accurate species classifications, we can create precise local safety recommendations, augment life history studies, and provide answers to victims. |
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3. Determinants of Intraspecific Genetic Diversity in Neotropical Amphibians. Luis Amador*, University of New Mexico; Lisa Barrow, University of New Mexico amadoroyola@gmail.com
Distinct evolutionary, ecological, and geographical factors can determine intraspecific genetic variation and influence the diversification and extinction of populations and species. The Neotropical region has the highest alpha diversity on the planet, and several studies have investigated the origin and maintenance of this diversity. However, determinants of intraspecific genetic diversity within this region have been poorly studied. Using amphibians as a study system, we investigate genetic variation within species of Anura and Caudata and provide insights into how life-history traits, phylogeny, and environment influence intraspecific genetic variation. Currently, we are working to identify predictors of genetic diversity for Neotropical amphibians using open-access databases; traits, genetic sequence, and geographic data: and under an approach that combines repurposed data, machine learning, and phylogenetic comparative methods. We have compiled 6,885 mtDNA sequences from 560 amphibian species (431 frogs and 129 salamanders). Our initial results demonstrate the relative importance of different predictors on amphibian genetic diversity. In addition, this information allows us to test our amphibian dataset with distinct predictors that have explained genetic diversity in animals previously, such as life-history traits (e.g., reproductive strategy – larval stage or direct development) as well other factors previously reported to have major influence, such as geographic factors. The results that we are obtaining could play a key role in the guidance of development of new methodological and conservation strategies for amphibian species, due the important genetic variation and high variety of life histories founded in Neotropical amphibians. |
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4. Diet and Gill Raker Morphology in Surfperches (Embiotocidae). Ayomikun Akinrinade*, University of Washington Bothell; Jeffrey Jensen, University of Washington Bothell ayomikun.akinrinade@gmail.com
The North Pacific fish family Embiotocidae (surfperches) shows remarkable dietary diversity despite being composed of only 23 species. The family includes feeding specialists and generalists, substrate feeders and open water feeders, species that feed on immobile hard-shelled prey, and species that feed on highly mobile prey. Much attention has been given to their oral jaws and their well-developed pharyngeal jaws, but little attention has been given to variation in their gill rakers despite the relationship between gill raker diversity and trophic diversity. In this study, we compare gill raker morphology, number, and length across the full phylogenetic and ecological range of the Embiotocidae. The phylogeny of surfperches is well understood, allowing us to map the evolution of gill raker variation and draw associations between gill raker variation, historical constraint, and ecological shifts. For example, within each of the subfamilies, planktivory is associated with more gill rakers relative to substrate feeding. Given their ecological range, well-described phylogeny, and tractable species number, surfperches are a model system for investigating the evolution of gill rakers in perciform fishes. |
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5. Geographic Range Expansion of the King Snake Eel, Ophichthus rex, to the Caribbean. Fernando Melendez-Vazquez, University of Oklahoma; Sara Cartwright*, Sam Noble Museum; Michelle Scharer-Umpierre, HJR Reefscaping; Kate Overly, TechGlobal, Inc. for NOAA; Dahiana Arcila, Sam Noble Museum isisrayn@gmail.com
The geographic distribution of the deep-water King Snake Eel, Ophichthus rex Bohlke and Caruso 1980 (Anguilliformes: Ophichthidae) is poorly understood and fragmentary. Early studies restricted the distribution of the King Snake Eel to the Western Atlantic including the northern Gulf of Mexico and from Florida to Texas. During a recent project inventorying the deep-sea fishes off the coast of Puerto Rico, a specimen of Ophichthus rex measuring 965 mm was collected in the summer of 2019, providing a substantial range expansion of this species into the Caribbean, and new insights into the biogeographic history of colonization of the genus Ophichthus. |
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6. Identification and recovery of a large Mola tecta from the North Coast of California. Allison Bronson*, California State Polytechnic University Humboldt; Emily Buck, California State Polytechnic University Humboldt; Marianne Nyegaard, Auckland Museum awb18@humboldt.edu
On November 27, 2021, what was assumed to be a dead Ocean Sunfish Mola mola was discovered washed up on Table Bluff Beach in Humboldt County, California. Though M. mola is relatively common in this region, the size of the Mola (182 cm TL) was exceptional. On December third, the specimen was measured, photographed, and dissected on the beach by a team of students and volunteers, then transported to California State Polytechnic University Humboldt for additional skeletal preparation. Upon further inspection, the morphology of the clavus diagnosed the specimen not as an Ocean Sunfish M. mola, but actually a Hoodwinker Sunfish M. tecta. Mola tecta is a primarily Southern Hemisphere species of sunfish only recently described in 2017 and not commonly documented in the Northern Hemisphere. With plans for its preparation underway, the Mola will soon become the first skeletal preparation of M. tecta housed at an American university. |
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7. Preliminary Mechanisms of Genetic Dispersal in the Florida Population of Smalltooth Sawfish, Pristis pectinata. Gregg R. Poulakis*, Charlotte Harbor Field Laboratory, Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission; Andrew K. Wooley, Charlotte Harbor Field Laboratory, Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission; Lukas B. Heath, Charlotte Harbor Field Laboratory, Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission; Dylan M. Yakich, Charlotte Harbor Field Laboratory, Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission; Kevin A. Feldheim, Pritzker Laboratory for Molecular Systematics and Evolution, The Field Museum gregg.poulakis@myfwc.com
Endangered smalltooth sawfish (Pristis pectinata) are found primarily in southwest Florida, but have re-emerged in the Indian River Lagoon, on Florida’s east coast. This large estuary was once a nursery for this species and supported large numbers from multiple life stages. Recent research has provided DNA from 12 tagged immature and mature individuals from the region. Individuals were genotyped using 15 microsatellite loci and compared to an existing pedigree of 1138 sawfish. We used COLONY to examine relatedness within the east coast group and between members of this group and the pedigree, which is mainly composed of individuals from nurseries in Everglades National Park and Charlotte Harbor. Five COLONY runs were performed with various settings to elucidate relationships and build confidence in interpretation of the results. Interpretations were aided by previous results, such as polyandrous mating, female philopatry, and reconstructed parental genotypes. We identified an adult female that gave birth in the Caloosahatchee River on the west coast in 2011 and again in the St. Lucie River on the east coast in 2021. In addition, based on size at capture data and DNA, one of the east coast females was likely born on the west coast and relocated to the east coast as a large juvenile and matured there. This research suggests that although males typically mediate gene flow, females can also contribute to gene flow in this population when they move between the east and west coasts of Florida, especially when they give birth in multiple estuaries. |
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8. Discovering the Hidden Diversity of Minnows of the Genus Phoxinus (Cypriniformes: Leuciscidae) from Switzerland through an Integrative Taxonomy Approach. Barbara Calegari*, University of Bern; Merline Roth, University of Bern; Conor Waldock, University of Bern; Bernhard Wegscheider, University of Bern; Dario Josi, University of Bern; Lukas Rüber, Natural Museum of Bern; Ole Seehausen, University of Bern barbara.calegari@gmail.com
Phoxinus is a freshwater genus of small fishes currently composed of 21 species widely distributed along Eurasian basins and North America. Currently, 13 valid species of Phoxinus are considered to occur in European drainages. Until recently, only two native minnow species were described as occurring in Switzerland, P. phoxinus distributed in the northern perialpine region, and P. lumaireul restricted to the southern drainages of the Alps. However, recent molecular studies evidenced the widely distributedP. phoxinus as a species complex with multiple independent lineages in Europe, some of which remain unknown to science. Due to the lack of inclusion of minnow populations from all Swiss freshwater drainages in molecular studies, the species occurrence in Switzerland, its geographical distribution limits, and the possible recognition of new species remained to be clarified. Seeking to delimitate the different lineages of Phoxinus distributed over all four major drainages in Switzerland, specimens collected from two large recently concluded biodiversity surveys and a new project have been investigated. An integrative taxonomy approach will be used including mitochondrial sequence data, microsatellite genotypes and new morphological data to assess the relationships between populations, and to correctly recognize and delimit the species. Preliminary results recognized at least four deeply divergent genetic lineages: three valid species (P. csikii, P. septimaniae, and P. lumaireul), and one divergent lineage, that could possibly be recognized under a historically available name of P. morella. Our results reveal much greater species diversity of Phoxinus in Switzerland than previously assumed. |
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9. Preliminary observation of site fidelity of female Caribbean reef sharks (Carcharhinus perezi) in The Bahamas based on mark-recapture. Beckah Campbell*, Arizona State University; Austin Gallagher, Beneath the Waves Non-Profit Organization; James Sulikowski, Arizona State University bacampb9@asu.edu
The Caribbean reef shark (Carcharhinus perezi) is a medium-bodied elasmobranch species highly associated with coral reef and insular shelf ecosystems throughout the greater Caribbean. This species has displayed site fidelity to The Bahamas where it is fully protected from fishing by The Bahamas Shark Sanctuary (~611,151.9 km2), and it serves as an environmentally (apex predator) and economically (shark diving industry) significant species. Despite this importance, minimal information is available concerning its key life history characteristics (i.e., reproduction, growth, movement, habitat use) across its range. To estimate movement behaviors of this species in The Bahamas, conventional tags were deployed on two adult, female C. perezi off south Stocking Island, Great Exuma. The two individuals were recaptured, identified by conventional tags, in approximately the same location four months later. Both females were found non-pregnant via in-situ ultrasonography upon both capture events, and reproductive hormone levels were found to have increased over the four-month period. Our preliminary study suggests that mature, female C. perezi may exhibit site-fidelity, although more data (i.e., acoustic telemetry, satellite-tagging) is needed to make definitive conclusions towards movement behaviors. |
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10. An Investigation of Personality in the Creek Chub (Semotilus atromaculatus). Jacob Barrett*, Austin Peay State University; Mollie Cashner, Austin Peay State University jbarrett10@my.apsu.edu
An increasingly relevant topic in the field of behavioral ecology is the study of animal personality, or individual differences in behavioral traits that are consistent across time and contexts. Personality has been identified in a wide range of animal taxa and has been linked to several ecological characteristics, including dispersal, habitat use, and foraging activity. Importantly, extreme tendencies in traits such as boldness and sociability have been implicated in a number of well-documented range expansions and species invasions. However, few studies have investigated personality in native fauna with more localized dispersal patterns, and information regarding the existence of personality in fishes native to the southeastern United States is particularly lacking. To that end, we characterize personality traits of Creek Chub (Semotilus atromaculatus). Semotilus atromaculatus presents a unique opportunity to investigate personality-dependent processes due to its piscivorous diet, use of its nests by nest-associating minnows, and its status as a colonizer of intermittent streams. We measure sociability (tendency to shoal), boldness (latency to emerge from refuge), and exploration tendency (movement in a novel environment), and test the predictions that: (i) individual S. atromaculatus behave consistently and (ii) S. atromaculatus exhibit behavioral syndromes, or correlated suites of behaviors. |
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11. Aspects of life-history variation in facultatively paedomorphic Western Tiger Salamanders in the Northern Plains. Christopher Cannon, Southeastern Louisiana University; Christopher Beachy*, Southeastern Louisiana University christopher.beachy@selu.edu
Throughout the range of the Western Tiger Salamander, Ambystoma mavortium, individuals often express paedomorphosis (i.e., the retention of larval features after sexual maturation is attained). The causes of this pattern of life cycle variation may vary geographically. We examined 340 individuals that were captured and preserved from 2006-2013 from several localities in northwest and northcentral North Dakota. The ponds and lakes in this region exhibit high productivity during the summers, and will either dry completely prior to onset of winter or be covered in thick ice. Salamanders commonly overwinter in ponds and lakes that have ice cover. For each salamander, we determined SVL, sex, maturation status (sexually mature or juvenile), and life-history status (larval, transforming, or fully transformed). Paedomorphs are very large (mean SVL = 117 mm), and are larger than both juvenile larvae and transformed adults. Males are more likely to express paedomorphosis than females. These data support the idea that paedomorphosis in these locations is due to rapid larval growth. Previous work has shown that paedomorphic females are much more likely to experience a post-maturation metamorphosis than males. Given the unpredictability of pond and lake duration, the value of paedomorphosis varies between sexes and across years and suggests that this polymorphism represents a plastic response to unpredictable habitat and the differential sex-specific value in expressing paedomorphosis. |
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12. Sharks As Exfoliators: Widespread Chafing Between Marine Organisms Suggests an Unexplored Ecological Role. Lacey Williams, Rosenstiel School of Marine and Atmospheric Science, University of Miami; Alexandra Anstett*, Rosenstiel School of Marine and Atmospheric Science, University of Miami; Victor Bach Muñoz, Rosenstiel School of Marine and Atmospheric Science, University of Miami; John Chisholm, Massachusetts Division of Marine Fisheries; Chris Fallows, Apex Shark Expeditions; Jonathan Green, Galapagos Whale Shark Project; Jesús Erick Higuera Rivas, Protección y Conservación Pelágica AC; Gregory Skomal, Massachusetts Division of Marine Fisheries; Megan Winton, Atlantic White Shark Conservancy; Neil Hammerschlag, Rosenstiel School of Marine and Atmospheric Science, University of Miami alexanstett@gmail.com
Interspecies chafing, whereby an organism rubs its body against another organism, is hypothesized to serve as a mechanism for bacteria and parasite removal. In marine systems, fishes have been observed to chafe against sharks, although the frequency and relevance of this behavior is not well known. This study explored the prevalence of this unique behavior, the only known phenomenon of prey rubbing against a predator. We documented 47 incidents of 13 different species of fish chafing against eight different species of sharks across 13 locations around the world. These observations raised three questions: 1. What is the benefit of rubbing against a shark 2. What is the impact of chafing behavior on sharks, and 3. Does chafing influence fish and shark ecology? It is possible that shark dermal denticles provide a more effective surface for removing bacteria and parasties than other objects, which could explain why fish actively pursue their potential predator in order to chafe. The chafing behavior may also present a parasitic relationship since several instances were recorded of the shark negatively responding to chafing fish. Our observations suggest that chafing may be a more widespread and ecologically significant than previously recognized since we observed this behavior occurring amongst species with varying life histories and within different habitats. The frequency and global occurrence of interspecific chafing on sharks necessitates further study to better understand this phenomenon and its consequences for both fish and sharks. |
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13. Occupancy Modeling and Detection Probability of the Caddo Madtom (Noturus taylori), a Narrowly Distributed Endemic in the Ouachita Highlands. Brittany L. McCall, Arkansas State University; Brook L. Fluker*, Arkansas State University bfluker@astate.edu
The Caddo Madtom (Noturus taylori) is a species of greatest conservation need in Arkansas and currently under consideration for listing under the U.S. Endangered Species Act because of restricted distribution, limited suitable habitat, and scarcity of life-history and distributional data. A recent genetic study and sampling survey provided some evidence that populations of N. taylori were more stable than previously thought, but there has not been a detailed occupancy study for N. taylori that spanned beyond historical collection localities. Thus, the objectives of this project were to provide updated information on distribution, occupancy, and habitat suitability for N. taylori. During summer of 2021, we conducted snorkel surveys for N. taylori and collected in-stream habitat variables at 54 randomly selected locations throughout the upper Ouachita, Caddo, and Little Missouri river drainages. We visually detected a total of 85 N. taylori at 17 of 54 locations, three of which represent new occurrence records for the species. Site occurrence and abundance of N. taylori varied among drainages (Caddo River: 9/17 sites, N = 55; Ouachita River: 6/17 sites, N = 27; Little Missouri River: 2/20 sites, N = 3). Visual detection at two locations in the Little Missouri River has important conservation implications since N. taylori has not been collected in the drainage since 1972. Surveys will be repeated in summer 2022 to complete the multi-year occupancy, detection probability, and habitat suitability estimates for N. taylori. Results from this study will aid in future listing decisions by state and federal agencies. |
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14. Thermal Performance of Wood Frogs (Rana sylvatica): a case of countergradient variation. Yara Alshwairikh*, Yale University; A. Z. Andis Arietta, Yale University; David Skelly, Yale University yara.alshwairikh@gmail.com
Amphibians are among the most imperiled taxa, subject to threats including climate change. Thermal sensitivity of ectotherms is well documented and may affect how species respond to changing thermal environments. One potential response could be via evolutionary adaptation, but we know little about the extent of local adaptation of key traits. For these reasons I have focused on estimating thermal sensitivity of locomotor traits in anurans using thermal performance curves (TPC). Specifically, I estimated TPCs of wood frogs’ (Rana sylvatica) jumping performance across a temperature gradient. For adult wood frogs, jumping is an important trait for escaping predators, moving to breeding ponds in the spring, capturing prey, and post-breeding dispersal. I collected adult wood frogs from two populations in Connecticut, USA at two sites characterized by different climate regimes and spanning two climate zones. The “Coastal” site is characterized by a warmer active season (2.2 oC warmer), less annual precipitation, and less snow compared to the “Interior” site. We measured the maximum jump distance of each frog at 8 temperatures between 6 to 30 oC. I fit generalized additive mixed models to generate thermal performance curves. Preliminary results suggest that the optimal performance temperature for the Interior population is warmer compared to the Coastal population. These population differences are consistent with countergradient variation, a pattern seen in other wood frog traits. |
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15. Ecological Association of Early Life History Stages of Fishes with Benthic Algae. Carly Lynn Strange*, College of Charleston; Antony Scott Harold, College of Charleston strangecl@g.cofc.edu
Estuaries, specifically the nursery habitats within them, are critical to the growth, reproduction, and survival of fishes that play ecologically and economically important roles within coastal ecosystems. Algal beds are important structures that contribute to these nurseries, providing safety from predation and harsh environmental conditions and ample food resources. The South Carolina coastline is low in seaweed biomass and typically exhibits a bare, mudflat substratum; however, since the introduction of Gracilaria vermiculophylla, an invasive alga from Asia, the community composition of benthic organisms has drastically changed. With the facilitation of tube-forming polychaetes which provide a substrate for attachment, this alga has colonized upper subtidal substrates of sand and silt and created a vegetated nursery structure where one was previously sparse. This project aims to document and analyze the diversity and abundance of larval and juvenile fishes in estuarine habitats that are hosted within assemblages of benthic algae, dominated by G. vermiculophylla. To investigate this relationship between the algae and early life history stages of fishes, quantitative samples of fishes will be taken from varying degrees of algal coverage and analyzed to evaluate the effect of algal density on fish species diversity, richness, and body size. For this study, comparisons on diversity index, species richness, and mean body size of selected common species will be done between three major categories: sites absent of benthic algae, sites with sparse algal coverage, and sites of dense algal coverage. Comparisons will also be made with respect to spatial and temporal elements. |