Heritability of cold tolerance in red drum - Texas A&M University (TAMU) Scholar

AbstractHeritability (h 2) 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 two sires) and were mixed in three commongarden replicate tanks for cold tolerance challenge. All offspring were assigned postmortem to parents based on genotypes at nuclearencoded microsatellites. The cold tolerance trial was initiated when offspring were 230251 d old (total length mean SD = 182 26 mm). Temperature was decreased progressively from 25C to 3C over a 30d 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 coolingdegreehours (CDH) index. The h 2of cold tolerance was estimated using an animal mixed model and a restricted maximum likelihood algorithm. The h 2 (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.

Ma, Liang||Ma, Liang||Saillant, Eric||Saillant, Eric||Gatlin, Delbert MIII||Gatlin, Delbert MIII||Neill, William H||Neill, William H||Vega, Robert R||Vega, Robert R||Gold, John R||Gold, John R

Heritability of cold tolerance in red drum Academic Article