Effect of temperature on phosphorus losses and phosphorus retention insilver perch, Bidyanus bidyanus (Mitchell 1838), (Teraponidae) fed onartificial diets

摘要

Silver perch, Bidyanus bidyanus (Mitchell 1838), were reared in glass aquaria and fed on three diets containing 53%, 45% and 36% protein, and 1.31%, 1.16% and 1.28% phosphorus, respectively, in order to investigate the phosphorus losses and phosphorus retention at 25 and 30 degrees 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 decreased linearly during the remaining 24 h. The daily orthophosphate output was observed to increase at the higher temperature and was significantly higher at 30 degrees C compared to 25 degrees C (P<0.05). Phosphorus retention by silver perch was significantly better at 25 degrees C than at 30 degrees C (P < 0.05).