Session 3: ASIH Stoye General Ichthyology IRoom: Ballroom 111C2022-07-28 13:30 - 15:00 |
| Moderator: Lily Hughes |
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1. 13:30 Periodic Environmental Disturbance Drives Repeated Ecomorphological Diversification in an Adaptive Radiation of Antarctic Fishes. Elyse Parker*, Department of Ecology & Evolutionary Biology, Yale University, P.O. Box 208106; Katerina L. Zapfe, Department of Bioinformatics and Genomics, University of North Carolina; Jagriti Yadav, Department of Bioinformatics and Genomics, University of North Carolina; Bruno Frédérich, Laboratory of Functional and Evolutionary Morphology, FOCUS, University of Liège; Christopher D. Jones, Antarctic Ecosystem Research Division, NOAA Southwest Fisheries Science Center; Evan P. Economo, Biodiversity and Biocomplexity Unit, Okinawa Institute of Science and Technology Graduate University; Sarah Federman, Plenty Unlimited Inc.; Thomas J. Near, Department of Ecology & Evolutionary Biology, Yale University, P.O. Box 208106; Alex Dornburg, Department of Bioinformatics and Genomics, University of North Carolina chantal.parker@yale.edu
The ecological theory of adaptive radiation has profoundly shaped our conceptualization of the rules that govern diversification. However, while many radiations follow classic early burst patterns of diversification as they fill ecological space, the longer-term fates of these radiations depend on many factors, such as climatic stability. In systems with periodic disturbances, species-rich clades can contain nested adaptive radiations of subclades with their own distinct diversification histories, and how adaptive radiation theory applies in these cases is less clear. Here, we investigated patterns of ecological and phenotypic diversification within two iterative adaptive radiations of cryonotothenioid fishes in Antarctica’s Southern Ocean: crocodile icefishes and notoperches. For both clades, we observe evidence of repeated diversification into disparate regions of trait space between closely related taxa and into overlapping regions of trait space between distantly related taxa. We additionally find little evidence that patterns of ecological divergence are correlated with evolution of morphological disparity, suggesting that these axes of divergence may not be tightly linked. Finally, we reveal evidence of repeated convergence in sympatry that suggests niche complementarity. These findings reflect the dynamic history of Antarctic marine habitats, and may guide hypotheses of diversification dynamics in environments characterized by periodic disturbance. |
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2. 13:45 Pao! A revision of an enigmatic genus of freshwater pufferfishes. Gabriel Somarriba*, Florida Museum of Natural History; Diego Elías, LSU Museum of Natural Science; Pasakorn Saenjundaeng, Khon Kaen University; Prosanta Chakrabarty, LSU Museum of Natural Science; Larry Page, Florida Museum of Natural History gabe.somarriba@ufl.edu
The pufferfishes in the genus Pao (Tetraodontidae) represent the largest entirely freshwater clade of fishes in the Tetraodontiformes, currently containing 15 species inhabiting rivers, reservoirs, swamps, and lakes throughout Thailand, Cambodia, Vietnam, Southern China, Laos, Borneo, and Indonesia. This group has a deficient taxonomic history due to the peculiarities of the fishes themselves, which include a dearth of diagnostic morphological characters, variability of color pattern, small sample size in collections, and poor species descriptions lacking detail. For these reasons, much uncertainty surrounds the distribution and identification of these fishes. Interestingly, some species of Pao are capable of sequestering saxitoxin, a potent neurotoxin for humans. Therefore, proper identification of these species is of particular importance for local fisheries because some species are eaten, which has resulted in numerous documented cases of severe poisoning. This study aims to resolve these phylogenetic issues, first by using genomic scale data to create a comprehensive species tree for the genus, and second by revising the taxonomy of Pao to help identify diagnostic characters in the light of a robust phylogenomic framework. In revising Pao, we hope to create a practical key for identification of the species. |
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3. 14:00 Verification of Giant Sea Bass (Stereolepis gigas) Spawning: Through Auditory Observations. Elizabeth Burns*, California State University, Northridge; Michael Franklin, California State University, Northridge; Larry Allen, California State University, Northridge elizabeth.burns.467@my.csun.edu
Giant Sea Bass (GSB), Stereolepis gigas, is the largest marine bony fish off the coast of California, an apex predator, and is currently classified as critically endangered by IUCN Red List. Despite recent studies on GSB, there is no documentation of their spawning and related reproductive behaviors in their natural environment due to their depressed population size. Previous studies have shown GSB capable of producing a variety of sounds (many sounding like a “boom”). Past studies have observed that the closer in proximity you are to a GSB spawning aggregation the louder and more numerous GSB sounds are heard. In these spawning aggregations “booms” have been observed to be linked with antagonistic behaviors towards GSB males by other GSB males. Indicating that sound production is most likely apart of spawning. In the summer of 2019 novel reproductive sounds labeled “snares” were recorded during successful spawning events of captive GSB. These “snares” have only been recorded during spawning. Using the ‘R’ package ‘warbleR’ we examined audio samples gathered in the summers of 2014, 2015, and 2019 to identify “snare” sounds recorded at GSB spawning aggregations. We hypothesize that GSB vocalization occurs frequently during spawning and is used in combination with courtship behaviors to signal reproduction readiness. This talk explores the in-progress investigation and identification of these hypothesized acoustical behaviors exhibited by GSB during spawning. I argue that by identifying these behaviors, we will be able to verify GSB spawning when these auditory behaviors are observed during their period of spawning. |
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4. 14:15 Vertical Orientation and Schooling: Behavioral Description of the Cutlassfish, Trichiurus lepturus. Cole Schmitt*, Department of Biological Sciences, California State University Chico; Murilo Pastana, Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution; Katherine Bemis, NOAA National Systematics Laboratory cjschmitt@mail.csuchico.edu
Vertical orientation, in which a fish orients its body perpendicular to the ocean floor, is an unusual behavior, but one that has evolved multiple times in Actinopterygii. We reviewed the literature, made new observations on ROV videos, and found that vertical orientation occurs in at least 15 families. Of these, all vertically orienting species have been observed as single individuals or in pairs, except for shrimpfishes (Centriscidae), which school vertically, head down, in large numbers. We document a second group of fishes that schools vertically in the water column, Cutlassfish, Trichiurus lepturus (Trichiuridae). In 2019, the Schmidt Ocean Institute ROV SuBastian recorded off Costa Rica a large, vertically oriented school of T. lepturus at a depth of 320 m. We analyzed a 40-minute high definition ROV video to describe vertical orientation and schooling in T. lepturus. The number of T. lepturus in view of the ROV ranged from 11-628 individuals. Almost all (98.7%) fish in the school were vertically oriented, head up in the water column. Our observations showed these fish positioning their dorsal fins in a similar direction while schooling. We observed schooling T. lepturus to use two forms of locomotion: (1) dorsal fin undulation, which the fish used to maintain position and move precisely up and down in the water column; and (2) body undulation, which the fish used to rapidly move up or down. Our description of vertical orientation and schooling in T. lepturus highlights this unusual behavior and will facilitate future comparisons in actinopterygians. |
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5. 14:30 Phylogenomic history of the Blacktail Shiner complex (Cyprinella venusta, Cypriniformes: Leuciscidae) and its taxonomic implications. Soren Johnson*, Southeastern Louisiana University; Kyle Piller, Southeastern Louisiana University soren.d.johnson@gmail.com
The Blacktail Shiner,Cyprinella venusta (Cypriniformes: Leuciscidae), is a species of freshwater fish that is abundant in lotic systems throughout the southeastern United States. Currently this species has three recognized subspecies (C. v. cercostigma, C. v. stigmatura, and C. v. venusta) based on phenotypic differences across their range. The validity of these subspecies has been questioned by past phylogenetic studies using mitochondrial genetic data. Our study used reduced representative genome sampling (specifically ddRADseq) data to infer a maximum likelihood phylogeny and assess the population structure of the Blacktail Shiner. These results were then compared against the currently recognized subspecies and the previously inferred mitochondrial phylogeny. Our results, using ddRAD data, were similar to the previous mitochondrial phylogeny, but it does not coincide with the morphologically based subspecies. Based on our results, the taxonomy does not agree with the inferred clades of Blacktail Shiners. Future studies should focus on re-evaluating the taxonomic status of the Blacktail Shiner complex in light of our results. |
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6. 14:45 Phylogenomics of African Labeo (Cypriniformes: Cyprinidae): resolving phylogenetic relationships and intrageneric systematics with emphasis on Central African species. Tobit Liyandja*, 1.; Elisabeth Alter, California State University; Brian Sildlauskas, Oregon State University; Melanie Stiassny, AMNH liyandja@gmail.com
Labeoconstitutes the largest genus within Labeonini (sensu Tan & Armbruster 2018) with 72 recognized species in Africa where they comprise a major component of the herbivore/detritivore guild and are of considerable socio-economic importance in artisanal and commercial fisheries. Additionally, the wide variety of habitats and a pan-African distribution of Labeo make the group an excellent model to investigate diversification patterns, eco-phenotypic variation, and the biogeographical events underpinning their radiation. However, previous attempts to elucidate Labeo systematics using either molecular or morphological data have failed to produce congruent and robust results, and much taxonomic and nomenclatural confusion remains. Here we present the first large-scale phylogenomic analysis of the genus using 1571 ultraconserved elements (UCEs) from 81 taxa including 52 recognized, 25 potentially unrecognized (cryptic), and four outgroup (Asian) species. Both concatenated and coalescence-based phylogenetic analyses strongly support the monophyly of AfricanLabeo and recover three main clades, two pan-African and one more restricted in distribution, and these can be divided into at least nine subclades (groups). With the single exception of the L. umbratus-group, none of the previously proposed morphological groupings of Reid (1985) are resolved as monophyletic suggesting rampant morphological convergence across the radiation. Interspecific relationships are well resolved with 92% of nodes having high bootstrap support. Numerous previously unrecognized taxa have been identified and our study provides a solid framework for the taxonomic revision of Labeo, a task critical for the development of sound fisheries resource management of these important food fishes across the continent. |