Appropriate Diet and Stocking Density for Sea Cucumber (Holothuria scabra) Larvae Rearing

Abstract

Overexploitation of sea cucumbers especially Holothurians is not a new issue, as this species has been highly demanded and traded at high price in Asian dried seafood market. As the wild seed supply has shown a substantial decline, hatchery production is urgently needed to supply the aquaculture industry. However, many are still struggling with the larviculture of Holothuria scabra. In this study, suitable diet (Nannochloropsis sp., Chaetoceros calcitrans and combined diet) and stocking density (1, 1.5 and 2 larvae ml ⁻¹) for H. scabra larvae are tested in a factorial experiment. The experiment was carried out in plastic containers randomly arranged in a water bath at temperature 29-30°C. Result shows that, there was a strong interaction between diets and stocking density on the growth of the larvae (p=0.000). Single species of Nannochloropsis sp. at 1.5 larvae ml ⁻¹ demonstrated the highest growth (109.69± 8.21). On the other hand, single species of C. calcitrans also at 1.5 larvae ml ⁻¹ enhanced the metamorphosis of auricularia into doliolaria stage. However, the survival rate was not significantly affected by the diets and stocking density (p= 0.974) although single species of Nannochloropsis sp. at 2 larvae ml ⁻¹ has the highest survival (1.2±1.05). For a stocking density of 1.5 larvae ml ⁻¹, it is recommended to feed the larvae with Nannochloropsis sp. and C. calcitrans for higher growth and faster metamorphosis, respectively.