OXYGEN-CONSUMPTION AND AMMONIA-N EXCRETION OF PENAEUS-CHINENSIS (OSBECK, 1765) JUVENILES AT DIFFERENT SALINITY LEVELS (DECAPODA, PENAEIDAE)

Oxygen consumption (O-2 mg/g/h) of Penaeus chinensis (Osbeck, 1765)juveniles (0.078 +/- 0.011 g) appeared to increase with increase of salinity over the range of 15, 20, 25 and 30 ppt, while ammonia-N excretion (mg/g/h) displayed an inverse relationship,vith salinity. Both oxygen consumption and ammonia-N excretion of prawns in 25 and 30 ppt was relatively stable. However, prawns al low salinity (15 and 20 ppt) consumed less oxygen and excreted more ammonia-N. It is suggested that catabolism of amino acid is required to reduce the internal osmolality of prawns which utilize amino acid as fuel to provide the necessary energy for hypo-regulation of P. chinensis.