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Timm LE, Tribuzio C, Walter R, Larson WA, Murray BW, Hussey NE, Wildes S. Molecular ecology of the sleeper shark subgenus Somniosus (Somniosus) reveals genetic homogeneity within species and lack of support for S. antarcticus. J Hered 2022; 114:152-164. [PMID: 36477342 DOI: 10.1093/jhered/esac064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 12/06/2022] [Indexed: 12/12/2022] Open
Abstract
Abstract
Inferences made from molecular data support regional stock assessment goals by providing insights into the genetic population dynamics of enigmatic species. Population genomics metrics, such as genetic diversity and population connectivity, serve as useful proxies for species health and stability. Sleeper sharks (genus Somniosus) are ecologically important deep-sea predators, estimated to reach ages of 250-300 years and taking decades to reach sexual maturity. The subgenus Somniosus (Somniosus) is comprised of three species: S. pacificus, S. microcephalus, and S. antarcticus. Given the life history strategy of somniosids, they are vulnerable to overfishing and population declines. Further, data to assess the stocks of these species are limited. To address this deficiency, we used the reduced representation library method Restriction-site Associated DNA sequencing (RADseq) to conduct phylogenomic and population genomics analyses, providing novel information for use in stock assessments. Our results strongly support the species status of S. microcephalus (N = 79), but recover S. antarcticus (N = 2) intermixed within the S. pacificus (N = 170) clade. Population genomics analyses reveal genetic homogeneity within S. pacificus and S. microcephalus, and estimates of effective population size were in the hundreds for both species. Kinship analysis identified two first-degree relative pairs within our dataset (one within each species). Our results contribute new information for stock assessments of these uniquely long-lived species by providing the strongest molecular evidence to date for the synonymization of S. antarcticus and S. pacificus, as well as estimating population genomic metrics for each supported species within the Somniosus (Somniosus) subgenus.
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Affiliation(s)
- Laura E Timm
- Auke Bay Laboratories, Alaska Fisheries Science Center, 17109 Point Lena Loop Road , Juneau, Alaska 99801 USA
- University of Alaska Fairbanks, College of Fisheries and Ocean Sciences, 1965 Yukon Drive , Fairbanks, Alaska 99775 USA
| | - Cindy Tribuzio
- Auke Bay Laboratories, Alaska Fisheries Science Center, 17109 Point Lena Loop Road , Juneau, Alaska 99801 USA
| | - Ryan Walter
- California State University Fullerton, College of Natural Sciences and Mathematics, 800 State College Blvd , Fullerton, California 92831 USA
| | - Wesley A Larson
- Auke Bay Laboratories, Alaska Fisheries Science Center, 17109 Point Lena Loop Road , Juneau, Alaska 99801 USA
| | - Brent W Murray
- University of Northern British Columbia, Department of Ecosystem Science and Management, 3333 University Way , Prince George, British Columbia V2N 4Z9 Canada
| | - Nigel E Hussey
- University of Windsor, Department of Integrative Biology, 401 Sunset Ave , Windsor, Ontario N9B 3P4 Canada
| | - Sharon Wildes
- Auke Bay Laboratories, Alaska Fisheries Science Center, 17109 Point Lena Loop Road , Juneau, Alaska 99801 USA
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