The African catfish (Clarias gariepinus) is highly regarded as an aquaculture species, extensively cultured in several countries. They are usually cultured without aeration, with the notion that aquatic oxygenation does not affect their growth performance due to their ability to tolerate low dissolved oxygen and their air-breathing capabilities. This study was thus designed to test the effects of different aeration regimes on the growth performance, feed utilization, and air-breathing behaviour of the species under varying aeration levels.
Fish of mean weight 41.8±0.16 g in four experimental groups (no aeration, 24-h moderate aeration, 24 h high aeration, and 12 h high nocturnal aeration) were set up in triplicate and run over a 12-week. Fish were fed with a commercial diet twice daily, corresponding to 5 % of their body weight. Data were collected on weight gain, weight gain percent, specific growth rate, feed conversion ratio, feed intake, and survival. The effects of aeration on the Air-breathing frequency (fab) were also measured. Results from the study showed a significant difference in the fab of C. gariepinus (p< 0.001). fab was highest in no aeration (6.08±0.20) and lowest in 24 h aeration (3.18±0.13). However, post hoc tests indicated no significant difference between the 24 h moderate aeration and 24 h high aeration. There were no significant effects of aeration on the measured and calculated growth and feed utilization indices. Although there was a trend of improved performance under the different aeration treatments compared to the no aeration control. Over a long-term cultured period, however, continuous 24 h high aeration might result in improved growth performance and feed utilization in the African catfish.