STUDY ON GROWTH AND SURVIVAL OF GIANT FRESHWATER PRAWN MACROBRACHIUM ROSENBERG II (DE MAN) LARVAE UNDER DIFFERENT CULTURE SYSTEMS

The present study was made to determine the effects of different larvi culture techniques. These techniques are operated for the survival of prawn larvae (from eggs to post larvae) on the water quality; the effect of stocking density on survival of the post larvae; and economical aspects of the three culture techniques. The three larvi culture techniques studied were: (1) the Clear water system with partial changes of water, (2) the green water system with a separate sub sand filter out side of the tank and (3) the green water system with a closed recirculation water system with a sub sand filter inside rearing tank. The results showed that the mean productions of metamorphosed post larvae prawn per liter of water in the three systems were compared. Fluctuations in the production of post larvae were greater in the clear water system than in the other two types of closed system. During the course of trails in the clear system, the ammonia level was intermittently high and might have caused high larval mortality.