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, and 1.31%, 1.16% and 1.28% phosphorus, respectively, in order to investigate the phosphorus losses and phosphorus retention at 25 and 30°C. The main path of phosphorus loss was found to be via faeces and was significantly higher at 30°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°C compared to 25°C (P <0.05). Phosphorus retention by silver perch was significantly better at 25°C than at 30°C (P <0.05).