Development of yellow perch ( Perca flavescens) broodstocks: Initial characterization of growth and quality traits following grow-out of different stocks

Abstract

Broodstocks of yellow perch ( Perca flavescens) were initiated from fertilized gametes obtained from wild fish taken from the Perquimans River (North Carolina), Choptank River (Maryland), Lake Winnebago (Wisconsin) and Lac du Flambeau (Wisconsin). Populations at these sites were chosen based on the results of a prior population genetics study of perch populations from the upper Midwest and East Coast (Grzybowski et al., 2010. Tr. Am. Fish. Soc. 139, 270–287). Criteria included drainage basins, overall genetic diversity, inbreeding coefficient, and the logistics of obtaining and crossing wild perch at each location. Fertilized gametes of all four stocks were reared under identical early life stage rearing conditions. Of the four stocks, Lac du Flambeau fish did not survive feed habituation. Progeny from the other three stocks were evaluated in a growth trial consisting of four replicate tanks per stock reared under identical conditions until one-year post hatch. Perquimans River and Choptank River fish did not differ in absolute growth rate (AGR), and both achieved an AGR 2.5 times as great as the Lake Winnebago fish. Average weights differed significantly between all stocks by the end of the growth trial with Perquimans River being the heaviest and Lake Winnebago the lightest. When each stock reached an average of 28 g, individuals were assigned to one of four size classes and the overall family contribution to each specific size class was determined by completing parentage analysis using microsatellites on a subset of individuals. Deviations from expected frequencies based on stocking proportions were observed in all stocks, suggesting a genetic link to growth and the ability to increase growth using selection. At the end of the growth trial, 40 individuals per stock were filleted for fillet yield and proximate analysis. No differences were observed in fillet yield, lipid, protein or moisture content. Significant differences were seen in arachidonic and eicosapentaenoic acid levels. The differences between stocks in growth suggest that the Perquimans River and Choptank River stocks would outperform the Lake Winnebago stock in intensive aquaculture environments. However, there may be other phenotypes such as disease resistance that are not evident from the growth trial in other stocks such as Lake Winnebago. The inability of Lac du Flambeau fish to survive early life stage rearing would indicate that these fish are not good candidates for broodstock development using the husbandry approaches employed in the current study.