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    P1: ASIH Storer Award, Ichthyology I

    2021-07-26   16:00 - 18:00

    To view the posters go to You will be able to chat one-on-one during the Monday poster session, the e-poster platform.

    1.  16:00  Evolution of the archerfishes (Toxotidae). Matthew Girard*, University of Kansas

    Archerfishes (Toxotidae) are best known for their ability to spit water out of their mouths, targeting terrestrial prey flying above or resting on overhanging vegetation. Although this hunting strategy has been widely popularized by main-stream print and video media, we lack a basic understanding of how archerfishes and the osteological features of their hunting mechanism have evolved. Prior work on archerfish systematics has been largely limited to taxonomic accounts and revisions, with relatively few phylogenetic hypotheses including more than one archerfish species in their analyses. In light of this, I perform a survey of the toxotid skeletal system and sequencing of genomic-level data to build a phylogeny of the Toxotidae. I then discuss the morphology of the archerfish hunting mechanism light of the phylogeny I recover.

    2.  16:00  Hide and Seq: Using genomic techniques (ddRADseq) to assess the population and phylogenetic structure of the Blacktail Shiner (Cyprinella venusta). Soren Johnson*, Southeastern Louisiana University; Kyle Piller, Southeastern Louisiana University

    The Blacktail Shiner, Cyprinella venusta (Cypriniformes: Leuciscidae), is an abundant fish in lotic systems of the southeastern United States. This species consists of three morphologically defined subspecies: C. v. venusta, C. v. cercostigma, and C. v. stigmatura. The validity of these subspecies has been challenged by mitochondrial genetic work which recovered four distinct clades that did not fully align with the ranges of the morphologically diagnosed subspecies. In order to help resolve this incongruence, we analyzed the population genetic structure and evolutionary history of this species using genomic techniques. We obtained tissue samples of C. venusta from across its range, representing all the subspecies and three of the four mtDNA clades. Double-digest restriction site associated DNA sequencing (ddRADseq) was conducted on these samples to produce single nucleotide polymorphism (SNP) data. The SNP data were used to infer a phylogeny and to assess population structure. From the phylogenetic and population structure analyses, we were able to better understand the evolutionary history and genetic structuring of C. venusta. Further analysis of more samples from different river basins will provide greater insight and give further evidence for taxonomic reclassification.

    3.  16:00  Genetic Assessment of Prionotus alatus and Prionotus paralatus in the northern Gulf of Mexico. Elizabeth Hunt*, Texas A&M University - Corpus Christi; Shannon O'Leary, St. Anselm College; Kevin Conway, Texas A&M University; David Portnoy, Texas A&M University - Corpus Christi

    Research on relationships among species in the Prionotini (family Triglidae) uncovered issues at the species level between Prionotus alatus and Prionotus paralatus, two species found on either side of a putative suture zone in the northern Gulf of Mexico (nGOM). Morphological work found intermediate phenotypes, suggesting potential hybridization, while molecular work using mitochondrial and nuclear loci found the two species did not exhibit reciprocal monophyly. Explanations for these results include, differing regional morphotypes within a single species, historic introgression, incipient speciation, or re-homogenization of two previously isolated genetic units. In order to reexamine the issue, we sampled P. alatusand P. paralatusacross their range in the nGOM for a genomic assessment to re-evaluate species designations and assess patterns of gene flow within and among species.

    4.  16:00  Novel Epigenetic Age Estimation in Wild-Caught Northern Gulf of Mexico Reef Fishes. Nick Weber*, Texas A&M University - Corpus Christi; Andrew Fields, Texas A&M University - Corpus Christi; William Patterson, University of Florida; Beverly Barnett, NOAA Fisheries; Christopher Hollenbeck, Texas A&M University - Corpus Christi; David Portnoy, Texas A&M University - Corpus Christi

    Age data are essential for estimating life history parameters and are thus critical for fisheries assessment and management. Traditional aging techniques, however, can be costly and time intensive, of low precision for some species, and are necessarily lethal when involving otoliths or vertebrae. Results of recent studies have demonstrated the degree of DNA methylation at certain CpG sites (cytosines followed by guanines) exhibits a strong correlation with chronological age, allowing the development of DNA methylation-based, age-predictive models referred to as epigenetic clocks. While epigenetic clocks have been developed for two fish species (European sea bass, Dicentrarchus labrax and zebrafish, Danio rerio) reared in laboratories, the potential application of epigenetic clocks to wild-caught fishes of management or conservation concern has not been evaluated. Herein, bisulfite-converted restriction site-associated DNA sequencing (bsRADseq) was used to identify CpG sites that exhibit age-correlated DNA methylation in red snapper (Lutjanus campechanus) and red grouper (Epinephelus morio). Species-specific epigenetic clocks developed from 100s of CpG sites in each species showed strong agreement between predicted and otolith-derived age estimates (r2 > 0.99 for both species). These results suggest epigenetic aging could provide an efficient and accurate approach to mass age fishes in a non-invasive manner, with important implications for fisheries management.

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