Estimation of repeatability and phenotypic correlation of reproductive traits in zebrafish Danio rerio

This study was conducted to estimate the repeatability and phenotypic correlation of reproductive traits of zebrafish Danio rerio, in captive condition. Breeding trials were conducted on 10 breeding pairs (2 male:1 female). The data on fecundity, fertility, hatchability and survival rate were recorded. The repeatability values were computed as a measure of consistency using the intra-class correlation coefficient. The repeatability estimates for fecundity, fertility, hatchability of total eggs, hatchability of fertilised eggs, survival rate of total eggs and survival rate of larvae were 0.701, 0.406, 0.336, 0.049, 0.295 and 0.314, respectively. Most of the reproductive traits analysed had moderate repeatability values barring the hatchability of fertilised eggs. The phenotypic correlation was calculated using the Pearson correlation method. The phenotypic correlations of fertility with hatchability of fertilised eggs; hatchability of total eggs; survival rate of total eggs and survival rate of larvae were highly significant (p≤0.01). This study provided valuable information on the consistency of reproductive parameters which would serve as model for conducting research in other fish species. Keywords: Genetic parameters, Phenotypic correlation, Repeatability, Reproductive traits, Zebrafish