Effect of stocking density on the hatching rate, larval and early juvenile rearing of edible sea cucumber Holothuria scabra (Jaeger, 1883)

Abstract

Fertilized eggs, auricularia larvae and three month old juveniles of <i style="mso-bidi-font-style:normal">H. scabra,</i> obtained from induced spawning were used for various experiments to assess the effect of stocking density on hatching rate, larval and early juvenile rearing of commercially important sea cucumber <i style="mso-bidi-font-style:normal">H. scabra</i>. Experiments were conducted for two days on hatching rate of fertilized eggs, for ten days on larval survival, growth and development and for 120 days on juvenile’s growth rate. An inverse relationship was observed between stocking density and hatching rate. Hatching rate varied between 15.1% at 8 eggs mL^-1 to a maximum of 66.4% at 0.5 eggs mL^-1. High survival, growth rate and fastest development of auricularia at stocking density 1 larvae mL^-1 indicated the optimum larval rearing conditions. Maximum growth rate in length and weight, suggested the stocking density 4.2 Nos. m^-2 is good for juvenile rearing. One way ANOVA on the differences in the hatching rate, larval growth and survival rate, juvenile growth rate both in length as well as in weight at different stocking densities indicated high level of significances (P<0.001).