Digestive system and growth performance of African catfish larvae Clarias gariepinus, (Burchell, 1822) maintained with biofloc technology with the addition of Chlorella sp.

Abstract

The production of catfish in aquaculture is still limited by the low supply of good quality seeds. One solution that can be done to overcome this problem is by the application of biofloc technology with microalgae addition. This study aims to evaluate the performance of digestive system, growth and robustness of the African catfish larvae maintained with biofloc technology and the addition of Chlorella sp. This research applied a completely randomized experimental design consisted of three treatments and triplicates, i.e larvae maintained with regular water exchange as the control (K), larvae maintained biofloc system (BF) and larvae reared with biofloc treatment and Chlorella sp. addition (BFC) with a rearing period of 15 days. Length growth, specific growth rate, condition factor, the activity of protease, amylase and lipase were not significantly different between treatments (P>0.05). The villi length in fish maintained in BF treatmen (136μm), was higher than those of BFC (121μm) and K treatments (105μm). The particle size of floc in BF and BFC were 0.44±0.025 and BFC 0.79±0.048 mm, respectively. The survival of catfish larvae in the BFC treatment was (51 ± 0,32)b, which was significantly higher (P<0.05) than those of K (45±0.52)a and BF (45±0.15)a. The results of stress test using 15 g L-1 water salinity demonstrated that the fish maintained in BFC has a higher survival (63%) than those of BF (47%) and K (43%). Overall results of the present study showed that the addition of Chlorella sp. could improve the growth performance and robustness of African catfish larvae against salinity stress.