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

Estimation of repeatability in zebrafish

Abstract

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