Program - Single Session

  • Presentation times are in Phoenix time (same time as Pacific Daylight Time)
  • Check back often as the schedule changes and sessions and presentation times are being adjusted

  • [Back to Session Listing]

    ASIH Stoye Award, Ichthyology II

    2021-07-21   10:45 - 12:15

    Moderator: Megan Osborne

    1.  10:45  IN-PERSON    Taxonomic Revision of the Sand shiner, Notropis stramineus (Cope, 1865). Amanda K. Pinion*, Department of Ecology and Conservation Biology, Texas A&M University; Daemin Kim, Department of Ecology and Evolutionary Biology, Yale University; Kevin W. Conway, Department of Ecology and Conservation Biology, Texas A&M University

    The Sand Shiner Notropis stramineus(Cope, 1865) is a medium-sized North American minnow with an expansive distribution east of the Continental Divide. Though N. stramineusis currently regarded as a single species, previous taxonomic authorities recognized two subspecies (N. s. stramineusand N. s. missuriensis), which are still recognized as valid by some authors.This classification comprising two subspecies is based largely on minor differences in scale-row counts between individuals inhabiting tributaries to the Great Lakes, upper Mississippi and Texas gulf coast river systems (N. s. stramineus) and those inhabiting the Missouri and Arkansas River systems (N. s. missuriensis). Using a molecular dataset comprising mitochondrial (Cytb) and nuclear (S7 intron 1 and recombination activating gene 1) loci, we assessed the phylogeographic structure of N. stramineusacross the range of the species. These results suggest that N. stramineus sensu lato may represent a super-species-complex, comprising multiple (4+) externally similar looking, yet genetically distinct species, the majority of which have yet to be formally recognized and diagnosed with phenotypic characters. We determine the taxonomic status of each genetically identified clade (= putative species) and compare standard qualitative and quantitative (meristics) skeletal characteristics for members obtained from representatives of each to uncover morphological traits useful for distinguishing between putative members of the N. stramineus super-species-complex. We assess whether consistent phenotypic variation exists in these characters across the range of N. stramineus sensu lato and whether this variation is congruent with genetic lineage membership.

    3.  11:15  IN-PERSON    Conservation Genomics of Spikedace (Meda fulgida). Alex Cameron*, University of New Mexico; Megan Osborne, University of New Mexico; Thomas Turner, University of New Mexico

    Spikedace (Meda fulgida) is a small-bodied minnow endemic to the Gila River Basin (Arizona and New Mexico). Spikedace has experienced dramatic declines due to changes in the natural hydrograph and the introduction of non-native species. To evaluate levels of genetic diversity, effective population size (Ne), and population structure we performed RAD-sequencing on 285 individuals from remaining wild populations, repatriated localities, and captive stocks. Genomic data (8,972 biallelic SNPs distributed across 25 chromosomes) revealed two distinct lineages of Spikedace; Aravaipa Creek and the Upper Gila River. Aravaipa Creek retains the majority of genomic variation remaining in this species, suggesting long-term demographic stability compared to other wild populations. Captive populations mirrored wild counterparts and there was little evidence of hatchery induced selection. Two repatriated populations (Fossil and Spring Creeks) had low effective sizes (Ne ≤ 100) and are susceptible to erosion of genomic diversity from genetic drift, which contrasts a third repatriated population (Blue River) that exhibited Ne > 500. Differences in Ne among repatriated populations suggest that historically occupied habitats now vary in quality and capacity to support repatriated fish. Therefore, habitat quality and stability may be more important criteria for successful re-establishment than genetic variation of stocked individuals in the short-term.

    4.  11:30  VIRTUAL    Evaluating the Importance of Reef-Based Resources for Reproduction in a Temperate Reef Fish. Benjamin Chubak*, California State University, Northridge; Mark Steele, California State University, Northridge

    California sheephead are among the most ecologically important fish on temperate reefs in California and Mexico, yet little is known about their reproductive ecology. Environmental factors can affect reproductive success in fish populations in a variety of ways, including by affecting diet. The goal of this study was to determine if any differences in reproduction among populations of California sheephead (Semicossyphus pulcher) were related to differences in diets among them. We measured the prey availability, diet composition, and batch fecundity of California sheephead on three large reefs within the Southern California Bight. Reproductive output, diet, and prey availability all differed between years, implying that variation in prey availability affected diet, which affected reproductive output. Understanding how changes to kelp forest habitat impact reproductive output can aid in future management efforts of economically and ecologically important species of fish.

    5.  11:45  VIRTUAL    SEASONAL MOVEMENT OF GIANT SEA BASS (STEREOLEPIS GIGAS) WITHIN THE SOUTHERN CALIFORNIA BIGHT. Jessica Peria*, California State University, Northridge; Mark Steele, California State University, Northridge

    The giant sea bass, Stereolepis gigas, is an endangered apex predator, found in the kelp forests of California. During the summer months, there are several predictable locations at which this species is known to aggregate, but during the winter, they leave these sites, most likely traveling offshore. It is thought that they most likely aggregate to spawn, but little is known about their use of aggregation sites from year to year. This study used spot pattern analysis (IS3) to identify a minimum of 48 unique individuals and monitor their use of multiple southern California aggregation sites between 2017 and 2021. The Spotting Giant Sea Bass database (a collection of photos submitted by researchers and citizen scientists) was then used to detect movement of these individuals to other sites along the coast. Multiple individuals were observed traveling among sites between spawning seasons, sometimes at long distances, but little movement appears to occur during the spawning season.

    6.  12:00  IN-PERSON    Assessment of vessel noise on hearing sensitivity in the soniferous Atlantic croaker (Micropogonias undulatus). Gina Badlowski*, University of New Orleans; Kelly Boyle, University of New Orleans

    Vessel traffic is rapidly increasing worldwide, yet associated noise pollution impacts on most organisms are unknown and minimally studied. Vessel noise is more pervasive than other sources (e.g. sonar, pile driving, seismic air gun blasts) and few studies exist for non-model species which likely experience this noise in the wild. The purpose of this study is to assess the impacts of vessel noise on saccular sensory hair cell density and hearing thresholds of an ecologically important, non-model species, the Atlantic croaker (Micropogoniasundulatus). Laboratory experiments with simulated vessel noise were conducted to test the effects of short-term exposure, a single 15-minute duration event, and longer-term exposure, three days of repeated vessel noise events (75 events per 24 hours with a two minute average duration). Following each experiment, half of the exposed (treatment) and non-exposed (control) fish were immediately euthanized and the left saccule hair cell bundles were labeled with fluorescent phalloidin and counted to assess hair cell density, while TUNEL assays were conducted on the right saccule to assess hair cell apoptosis. The remaining half of treatment and control fish were given an auditory evoked potential (AEP) to assess hearing thresholds immediately following the experiment. Preliminary results indicate that vessel noise may decrease sensory hair cell density within the saccule and may cause diminished hearing. For this common estuarine food web species, potential hearing loss is predicted to have negative impacts on spawning behavior and predator avoidance which can lead to greater ecological impacts.

    [Back to Session Listing]