Growth performance evaluation of Clarias gariepinus, Heterobranchus bidorsalis and heteroclarias under recirculatory and flowthrough aquaculture systems

Abstract

Aquaculture system design plays a critical role in influencing the growth performance and survival of cultured fish species, particularly in intensively farmed catfish. This study evaluated variations in growth performances and survival rates among two widely cultured catfish species in Nigeria (Clarias gariepinus and Heterobranchus bidorsalis) and their hybrid (Heteroclarias) under flow-through and recirculatory aquaculture systems. Three Hundred (300) hatchery bred fry (14 day old) each of C. gariepinus, H. bidorsalis and Heteroclarias were randomly selected and stocked separately in triplicate (100 fish/replicate) experimental plastic tanks (1.2 x 0.6 x 0.5m3 ) connected to recirculatory and flow-through systems. The fish were fed ad libitum four times daily with commercial feed (40% CP) for 60 days. Growth performances and survival rates of the fish were estimated according to standard formulae. Data collected at the end of the feeding trials were subjected to t-test and one way analysis of variance. Results showed that final mean weight and weight gain (WG) differed significantly (p < 0.05) among treatments. Fish reared in recirculatory system generally recorded higher final weights and weight gains when compared with those reared in flow-through system. C. gariepinus in the recirculatory system achieved the highest final weight (4.34 ± 0.13 g) and weight gain (4.25 ± 0.12 g), while the lowest values were observed in C. gariepinus and H. bidorsalis reared under flow-through conditions. Daily growth rate values ranged from 0.06 to 0.07 g day⁻¹, while specific growth rates ranged from 6.21 to 6.68%day⁻¹. The highest survival rate was observed in Heteroclarias reared in the recirculatory system (88.78 ± 1.09%) and lowest in H. bidorsalis under flow-through conditions (86.22 ± 0.62%). In conclusion, recirculatory systems enhanced catfish growth and survival, with the hybrid strain (Heteroclarias) showing superior growth performances when compared with the parent stock (C. gariepinus and H. bidorsalis) in both culture systems.