Spatio-temporal population genetic structure and mating system of red king crab (Paralithodes camtschaticus) in Alaska

Abstract

Population genetic data can be used to make inferences about the Population structure and mating system and inform management decisions of overharvested species such as red king crab (Paralithodes camtschaticus) in Alaska. Red king crab tissue and hemolymph samples were collected from 11 geographically distinct locations from Norton Sound through Southeast Alaska (n = 845). At six locations, two collections were taken at least one generation apart. Heterogeneity of allele frequencies over time was detected in three of the six locations examined, which suggested signs of recent population bottlenecks. An overall Fst = 0.025 (P <0.00 1) suggested moderate genetic differentiation among red king crab collections. A two-region model of spatial differentiation in which collections from Southeast Alaska diverge from those in the Gulf of Alaska and Westen Alaska was supported by pairwise Fst Values, homogeneity tests, Bayesian clustering, and discriminant analysis of principal components. However, spatial analysis of molecular variance suggests some finer-scale structuring within regions and greater differentiation occurs among collections within Southeast Alaska than among the rest of the collections. In addition to population genetic structure analyses, 24 female red king crab and their broods were collected from the Bering Sea. Ovigerous females and 20 offspring per brood were genotyped in order to determine whether multiple mating of a female occurred. There was no evidence of multiple paternity in any brood. The results of this study support continued management of distinct geographic groups within the Gulf of Alaska/Western Alaska/Western Alaska region and suggest that finer-scale management may be beneficial in Southeast Alaska.