Seasonal variations in the phosphorus contents of the muscle of catfishClarias bairachus L.
Seasonal variations were observed, in total acid soluble phosphorus, inorganic phosphorus and phosphorus in the muscle ofC. batrachus L. The maximum concentration of these constituents were recorded during April, May and June. Thereafter values decreased and the levels remained low during winter months. The observed changes have been correlated with feeding intensity, gonad maturation and spawning. The rise and fall of different phosphorus contents were found to coincide with high and low rate of feeding. There was a gradual rise in the values when gonads advanced towards maturity. The maximum concentration corresponded to the period of peak ripeness (April, May and June). The values declined during the spawning period which possibly indicate the utilization of these reserves for energy. The low phosphorus contents observed in post-spawning and winter appear to be the result of exhaustion of spawning.