Little is known about the behaviour of fish under culture conditions. Several factors may
have a direct effect on fish behaviour and its variations during the day. This study assessed the
effect of feeding method (continuous by self-feeders vs. twice a day hand-feeding), light
intensity (15 vs. 150 lx) and photoperiod [continuous light vs. 12 h darkness and 12 h light
(12D:12L)] on behaviour of juvenile African Catfish (Clarias gariepinus). Sixteen aquaria, each
with 30 fish (average initial weight of 55 g) were used during a 6-week experimental period.
Fish behaviour was recorded by direct observation. Fish were more active under hand-feeding
regime than under self-feeding. Fish spent more time swimming under continuous light than
under a 12D:12L. Furthermore, the time that fish spent swimming was higher at high light
intensity (150 lx) than under low light intensity (15 lx). Aggression was affected by photoperiod
and light intensity. Continuous light resulted in 41.6% more scars and wounds than the 12D:12L
photoperiod, while high light intensity resulted in 2.46 times more scars and wounds than low
light intensity. Fish that spent more time swimming and browsing were more aggressive, and
they had more scars and wounds on the body. Fish under the hand-feeding method showed a
higher activity during the morning compared to the afternoon. Fish also showed a higher
activity before each meal (morning and afternoon meals) than afterwards. These activities were
more evident during the mornings. The current study demonstrated that for juveniles of the