The effect of water hardness on the development of embryo and larvae of silver carp (Hypophthalmychthis molitrix)

Abstract

This study aimed to investigate the effect of water hardness on the fertilization rate, hatching rate, survival rate, and deformity rate of common carp larvae. In the experiment, fertilized eggs of silver carp were incubated in different water hardness levels of 70, 100, 130, 160, & 190 mg CaCO3/L, with a stocking density of 400 eggs/L. The experimental results showed that the fertilization rate was high (78.0 - 79.3%) and did not show significant differences between the treatments (P > 0.05). The hatching rate ranged from 41.0 to 54.0% and larvae stage had the highest survival rate of 54.0% at 70 mg CaCO3/L. The deformity rate of larvae ranged from 5.7 to 74.3% with the lowest observed at the 70 mg CaCO3/L. From the results of the study, it can be assumed that silver carp eggs should be incubated in an aquatic environment with a water hardness of 70 mg CaCO3/L.