Optimizing the stocking density is crucial for growth and survival of catfish, Clarias batrachus larvae

The effect of four (12, 18, 24, and 30 larvae L-1) stocking densities (SD) on growth and survival of catfish, Clarias batrachus larvae (1.47 cm and 0.03 g) was investigated in triplicates in glass aquaria for a period of 28 days. The larvae were fed with Tubifex sp. four times daily until satiation. The larvae reared at high SD (30 larvae L -1 ) showed significantly slower growth performance than those held at low SD (12 larvae L-1). Water quality parameters were found within the productive range (temperature: 28.7°C, DO: 6.1 mg L-1, pH: 7.8, and alkalinity: 379 mg CaCO3 L -1 ) for all treatments. The specific growth rate varied significantly in fish reared at high SD than at low SD on day 14 only, but on day 7, 21, and 28 there were no significant differences among the four treatments. Heterospecific growth was observed in high SD resulting in increased coefficient of variance of length and weight on final day. On the other hand, there was no effect of stocking densities on the survival rate of the larvae during the experimental period. Based on these findings, a stocking density of 18 larvae L-1 appears to be optimum for