PRODUCTION OF AUSTRALIAN RED CLAW CHERAX-QUADRICARINATUS IN POLYCULTURE WITH NILE TILAPIA OREOCHROMIS-NILOTICUS

Australian red claw crayfish Cherax quadricarinatus were cultured in m onoculture and in polyculture with male Nile tilapia Oreochromis nilot icus in nine 0.02-ha earthen ponds. Red claw with an average weight of 7 g were stocked in all ponds at 2/m(2). Tilapia with an average weig ht of 19 g were stocked in six ponds at either 0.5 or 1/m(2). A sinkin g 32% fish dirt and dry alfalfa hay was provided to all ponds as feed and forage. After 135 d, red claw survival was similar (19-24%) in all treatments while average weights were 76 g in monoculture and 48 g in both polyculture treatments. Lower than expected survival was a resul t of stress caused by poor shipping conditions. Tilapia survivals were similar (84-90%) in all ponds and had an average weight of 403 g when stocked at 1/m(2) and 444 g when stocked at 0.5/m(2). Red claws are g enerally considered non-aggressive, especially when compared with othe r clawed crustaceans. This lack of aggressiveness is suggested as a ca use for decreased growth in polyculture with tilapia.