Effects of different photoperiods on the growth and survival of cultured edible frog Hoplobatrachus occipitalis (Günther 1858) from tadpole to full metamorphosis

Abstract

ABSTRACT Three photoperiods designed as 24L:0D; 0L:24D and 12L:12D were used to culture Hoplobatrachus occipitalis (Günther 1858) tadpoles to evaluate the growth performance and survival rate. One hundred and eighty tadpoles were distributed into the three photoperiodic ponds for 20 weeks and fed with duck weed. The frogs reared using the 0L:24D photoperiod had significantly higher growth performance, survival rate and metamorphosis where the tadpoles reached full metamorphosis after 20 weeks, than the other two photoperiods (P < .05.) Full metamorphosis of the tadpoles was seen when the limbs have been fully formed, tails and gills have been completely absorbed, the eyes become bulgy and they are completely out of water breathing by their lungs. Higher growth performance, survival rate and metamorphosis in 0L:24D photoperiod could be attributed to complete utilization of food, low ammonia concentration and high dissolved oxygen. Commercial aquaculture of H. occipitalis tadpoles should be done in 0L:24D to obtain complete metamorphosis, survival and faster growth in less time. Using 0L:24D to culture the tadpoles and releasing them into the wild will decrease overexploitation of the species, thereby aiding in their conservation.