Impact of different rearing systems on survival, growth and quality of mud crab (Scylla paramamosain) megalopae reared from early zoeae

Abstract

This study aimed to compare the effects of four different rearing systems—namely clear water, green water, recirculating water and biofloc water systems—on survival, growth and quality of mud crab (Scylla paramamosain) megalopae reared from early zoeae. Twelve 60-L plastic buckets filled with 50 L of disinfected seawater were stocked with 20 larvae of zoea 1 (Z1) L−1. The larvae were fed both probiotic-enriched L-strain rotifers (Brachionus plicatilis) and probiotic-enriched Artemia (Artemia franciscana) in all systems. After 20 days of culture, the green water system resulted in the highest survival to megalopae than all the other systems. The survival of megalopae reared under the biofloc water system was similar to that of the clear water system, but both systems exhibited higher survival than the recirculating water system. However, larval growth performance was not affected by the various rearing systems. The quality of megalopae produced under these systems was determined by ammonia and simulated transport stress tests. The ammonia stress test did not show a significant difference in the quality of megalopae, but the simulated transport stress test demonstrated a significant effect of rearing system on the quality of mud crab megalopae. The resistance to the air exposure until the end of the 48 h of transport was observed in the green water system. Overall, the results of the present study revealed that the green water system is the most suitable for rearing Scylla paramamosain larvae from Z1 to megalopa stage.