Preservation of heritable ecological diversity within species and populations is a key challenge for managing natural resources and wild populations. Salmonid fish are iconic and socio-economically important species for commercial, aquaculture, and recreational fisheries across the globe. Many salmonids are known to exhibit ecological divergence within species, including distinct feeding ecotypes within the same lakes. Here we used 5559 SNPs, derived from RAD sequencing, to perform population genetic comparisons between two dietary ecotypes of sockeye salmon (Oncorhynchus nerka) in Jo-Jo Lake, Alaska (USA). We tested the standing hypothesis that these two ecotypes are currently diverging as a result of adaptation to distinct dietary niches; results support earlier conclusions of a single panmictic population. The RAD sequence data revealed 40 new SNPs not previously detected in the species, and our sequence data can be used in future studies of ecotypic diversity in salmonid species.
Ecological speciation Kokanee salmon SNPs RAD sequencing
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We thank Jeff Olsen at the USFWS Alaska Conservation Genetics Laboratory for sharing archived Jo-Jo Lake tissue samples and Carita Pascal for laboratory assistance. MTL was supported by a fellowship from the Carlsberg Foundation CF15-0721. WAL was supported by the H. Mason Keeler Endowment for Excellence and a US National Science Foundation Graduate Research Fellowship (Grant No. DGE-0718124). Any use of trade, firm, for product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
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