ABSTRACT

The effect of photoperiod on the African catfish(Clarias gariepinus )was carried out on 84 catfish juveniles of initial weight of 45.33±3.33g.Seven fish each were stocked in ponds of O.65mx0.98mx1m for the three treatments of 12L:12D,24D:OL and 18D:6L. each treatment was replicated three times and a water depth maintained at 40cm.For the photoperiod treatment of 24D:OL, au opaque material was used to cover the tank so as to achieve total darkness while that of 18D:6L was also covered but was allowed open for only 6 hours(8am- 2pm). The photopenod of 12L:12D was left open throughout the experiment period of 4 months data collection which consisted of weight gained as well as length of fish was taken every two weeks interval. Observations were noted down for swimming behavior as well as body scar in the three treatments.photoperiod can affects the performance and behavior of the African catfish(Clarias gariepinus ). Short period of light or no light(6L:18D and OL:24D) resulted in an increased growth compared to extended periods of light 18L:6D,12L:12D or more. Fish under longer periods of light(12L:12D and 18L:6D) showed higher swimming activity,more aggression,body injuries compared to those that were reared at shorter periods of light(OL:24D and 6L:18D). this shows that light plays an important role in the African catfish behavior and it's welfare. The increase in light hour reduced growth as well as weight gain.