Genomic population structure of Grass Pickerel (Esox americanus vermiculatus) in Canada: management guidance for an at-risk fish at its northern range limit.

Autor: Lujan, Nathan K., Colm, Julia E., Weir, Jason T., Montgomery, Fielding A., Noonan, Brice P., Lovejoy, Nathan R., Mandrak, Nicholas E.
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Zdroj: Conservation Genetics; Aug2022, Vol. 23 Issue 4, p713-725, 13p
Abstrakt: Eighty nine (42%) of Canada's 215 freshwater fish species have been assessed as at risk by the Committee on the Status of Endangered Wildlife in Canada. This study examines genomic population structure of the at-risk Grass Pickerel (Esox americanus vermiculatus), a small (≤ 33 cm) predatory fish that in Canada has a range spanning approximately 114,000 km2 of southern Ontario. Within this range it occupies approximately ten sites that are mostly shallow, weedy, and slow-flowing. Its populations and habitat are declining. This study defines population clusters and quantifies genomic diversity within and between populations based on > 5500 loci and > 950 SNPs from genomes of 66 individuals representing the subspecies' entire Canadian range. Ordination and STRUCTURE analyses revealed four major geographic/genomic clusters centered in the Georgian Bay-Severn River, southeastern shore of Lake Huron, Niagara Peninsula, and upper St. Lawrence River. Major clusters were distinguished by relatively high Hudson Fst values (0.205–0.480), with Georgian Bay-Severn River being consistently most distinct. The Niagara Peninsula major cluster contained an additional three discernable sub-clusters differentiated by Fst values as great or greater than major clusters, despite spanning only ca. 200 km2. Genomically distinct Niagara sub-clusters occurred in Abino Drain, Big Forks Creek, and Tea Creek. Samples from sites between both major and minor clusters exhibited admixture from adjacent clusters. Despite current management of Grass Pickerel under a single designatable unit throughout its Canadian range, we map considerable geographic population structure that should help guide the designation of additional conservation units. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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