Replacement of live feed by formulated feed: effect on the growth and spawning performance of Siamese fighting fish (Betta splendens, Regan, 1910)

摘要

Partial replacement of live feed (LF) with formulated feed (FF) was performed in Betta splendens to evaluate their growth, survival and reproductive performance. Three hundred B. splendens fry of uniform size (mean weight 0.19 gpl0.01) were equally distributed in five treatment groups with each of three replicates in glass aquaria of 35 L capacity. Fish were offered diets of different ratio of LF and FF like T1 (control) - 100% LF; T2 - 75% LF, 25% FF; T3 - 50% LF, 50% FF; T4 - 25% LF, 75% FF and T5 - 100% FF. Highest (P<0.05) body weight gain (% BWG) (67.1pl1.03) and specific growth rate (2.34pl0.02) were observed in the T2 group. Best feed conversion ratio was also found in T2 (2.40pl0.11), which was similar to T1 and T3. The highest survival rate (%) was recorded in T1, T2 and T3 groups (97pl1.7), which was similar to T4 and the lowest in T5 (49pl2.0). The highest gonadal weight (0.12 gpl0.01) and gonadosomatic index (15.17pl0.50) was observed in the T3 group during the first sampling after 63 days. No significant changes in spawning performance were observed in the second sampling after 21 days after first sampling. However, T4 group registered the highest fecundity and fertilized eggs at the end of 105 days of experiment. From the present study, it concludes that LF can be successfully replaced to the extent of 25% by FF without any detrimental effect on the growth, survival and spawning performance of B. splendens.