Effects of Extended-Rotifers Inclusion and Live Food-Enrichment with Probiotics on the Survival, Metamorphosis, Development Time and Growth of Mud Crab, Scylla paramamosain (Estampador) Larvae

Abstract

The present larval nutrition study was conducted to evaluate the effects of feeding probiotic-enriched rotifers inclusion mixed with Artemia until zoeal stages 4 (Z4) and Z5 on the survival, metamorphosis, development time and growth of mud crabs, Scylla paramamosain larvae. The efficiency of the feeding regime was tested by two-factor analysis. A 4×2 factorial experimental design with eight combinations of enriched or un-enriched or a mixture of enriched and un-enriched live food (factor 1) in each of two feeding regimes (factor 2) in triplicate was setup. After 24 days of larval cultivation, there were no significant (p>0.05) interactive effects between the two selected factors on survival and metamorphosis rate of larvae. Larval survival in all treatments, under both factors, decreased gradually (p<0.05) during the cultivation period. From 15 Days After Hatching (DAH), the survival and metamorphosis rates of larvae fed both enriched rotifers and Artemia were higher (p<0.05) than those of the larvae without enriched live food. Similarly, from 18 DAH onwards, the extension of rotifers inclusion mixed with Artemia until Z5, irrespective of enrichment, showed higher (p<0.05) survival, metamorphosis and growth of megalopa than when the rotifers were included only until Z4 stage. Overall, an amalgamation of extending rotifer feeding and enriching them at the same time with Artemia can result in considerable improvements in survival and metamorphosis which can in turn, have beneficial impact on the technical feasibility of a commercial crab hatchery.