A factorial experiment for heritability estimation of the reproductive traits in Persian sturgeon, Acipenser persicus

Abstract

Persian sturgeon (Acipenser persicus) is one of the most valuable species of fish native to the Caspian Sea and Iran's waters. Reproductive traits and their heritability have been evaluated in Persian sturgeon, Acipenser persicus. Six male and female fish (three of each) caught in southern Caspian Sea were crossed by using a 3×3 factorial, that is the result of mating between them was 9 treatments for heritability estimation and fertilization traits. Prior to the crossing, sperm density, motility, pH and osmolarity, percent spermatocrit, and the number of micropiles on the eggs surface were determined. Hatching percent was calculated at 5 h after fertilization and 405 eggs were measured for weight and diameter. Sperm concentration and number of micropiles had no significant effects on fertilization rate (P > 0.05). Sperm density also had negative correlations with fertilization (r = -0.603, P <0.01) and hatching rates (r =-0.175, P <0.01). However, fertilization was positively correlated with osmolarity (r = 0.511) and number of micropiles (r = 0.574). The correlation between osmolarity and hatching rate was 0.288 and between egg weight and its diameter was 0.698. Heritability estimates for egg weight and its diameter were 0.043±0.035 and 0.207± 0.103, respectively. The results for the additive genetic variation implied that the studied crosses could be exploited for genetic improvement of reproductive traits. The estimated heritability suggested that selection could be employed to improve genetically the weight and diameter of eggs.