Heritability of cold tolerance in red drum
Academic Article
Overview
Research
Identity
Additional Document Info
Other
View All
Overview
abstract
Heritability (h2) of cold tolerance was estimated for red drum Sciaenops ocellatus, an economically important sciaenid fish in the southern USA. Nineteen families were generated via environmentally induced spawning of multiple sets of five broodfish (three dams X two sires) and were mixed in three common-garden replicate tanks for cold tolerance challenge. All offspring were assigned postmortem to parents based on genotypes at nuclear-encoded microsatellites. The cold tolerance trial was initiated when offspring were 230-251 d old (total length mean SD = 182 26 mm). Temperature was decreased progressively from 25C to 3C over a 30-d period and was maintained at an average of 3.1C until all fish expired. Mortality began when temperature reached 5C. Cold tolerance of individual fish was quantified based on survival time and a cooling-degree-hours (CDH) index. The h2 of cold tolerance was estimated using an animal mixed model and a restricted maximum likelihood algorithm. The h2 (mean SE) estimate was 0.32 0.12 and indicated a significant genetic component to cold tolerance in red drum. Phenotypic correlations between cold tolerance and body weight or length were positive but low (0.18 and 0.23, respectively), suggesting that selective breeding for increased growth rate in red drum would not have a negative impact on cold tolerance in the selected strain. Copyright by the American Fisheries Society 2007.
