Optimization of feeding frequency for the brackishwater catfish, Mystus gulio during nursery rearing in net cages

Abstract

Four feeding frequencies of one (T1), two (T2), three (T3) and four (T4) times a day were evaluated as treatments on Mystus gulio in triplicate net cages (2×1×1 m) for a period of 60 days. Hatchery produced twelve-day old M. gulio fry (0.02 g/ 12 mm) stocked at 300 number/ net cage were fed with a CIBA formulated diet (Crude protein 30%) at 15-5% of the biomass daily. Fry attained significantly higher growth of 1.30±0.32 g at 3 times feeding a day compared to other groups (P<0.05). Percentage weight gain and specific growth rate were significantly higher in T3 (P<0.05), while there was no significant variation (P>0.05) between T3 and T4. Moreover, higher survival in 3 and 4 times feeding differed significantly from that of 1 and 2 times feeding a day (P<0.05). No significant differences were recorded among treatments for feed conversion ratio and coefficient of variation in the harvest weight, which ranged 2.03-2.94 and 0.184-0.374, respectively. Similarly, whole body composition of harvested fry revealed no variation in parameters among treatments. Therefore, a feeding frequency of 3 times daily is suggested for nursery rearing of M. gulio in net cage system.