Diel rhythms of feeding activity in African catfish, Clarias gariepinus (Burchell 1822)

Cycles of movement and feeding of African catfish, Clarias gariepinus (Burc hell 1822) fingerlings (113.48 +/- 1.87 mm total length) were studied using an infrared illumination and video recording system. The study was carried out over a 15-day period with a group of 40 fish held at 30 degrees C unde r a 12-h light:12-h dark photoperiod. The fish were nocturnal and took over 70% of their daily ration at night when given access to food 24 h a day. W hen feeding was restricted to the light phase, feeding activity decreased, but nocturnal feeding was restored from the second day after a return to 24 h food access.