An assessment of hatchery effects on Florida bass (Micropterus salmoides floridanus) microsatellite genetic diversity and sib-ship reconstruction

Abstract

Black bass populations have been augmented with aggressive aquaculture as a fisheries management tool over the past several decades. The purpose of our study was to estimate changes in genetic diversity and effective number of breeders (Nb) contributing to and represented in fingerling samples from two stages in the Florida bass (Micropterus salmoides floridanus) production process: post-fry grow-out and post-feed training. We screened 120 wild-sourced brood fish and 900 fingerlings representing two periods at nine microsatellite loci and determined relatedness (Rxy), effective number of breeders (Nb) and general diversity trends over the hatchery production process. The construction of putative full-sib partitions revealed that cohorts within stage 1 and 2 fingerling samples consisted of large numbers of small sib groups (80 and 55 groups respectively). Effective number of breeders calculated using the linkage disequilibrium method was estimated at 60–100 depending on the Nb parameters, representing a Nb/N of >0.5. Our assessment suggests that the current raceway breeding practice appear to be adequate at maintaining substantial portions of the genetic diversity of the breeding stock.