EFFECT OF TEMPERATURE ON PHOSPHORUS LOSSES AND PHOSPHORUS RETENTION IN SILVER PERCH, BIDYANUS-BIDYANUS (MITCHELL 1838), (TERAPONIDAE) FED ON ARTIFICIAL DIETS

Silver perch, Bidyanus bidyanus (Mitchell 1838), were reared in glass aquaria and fed on three diets containing 53%, 45% and 36% protein, an d 1.31%, 1.16% and 1.28% phosphorus, respectively, in order to investi gate the phosphorus losses and phosphorus retention at 25 and 30 degre es C. The main path of phosphorus loss was found to be via faeces and was significantly higher at 30 degrees C (P < 0.05). There was a sharp increase in orthophosphate excretion soon after meals, which decrease d linearly during the remaining 24 h. The daily orthophosphate output was observed to increase at the higher temperature and was significant ly higher at 30 degrees C compared to 25 degrees C (P<0.05). Phosphoru s retention by silver perch was significantly better at 25 degrees C t han at 30 degrees C (P < 0.05).