Impacts of Photoperiod Manipulation on Growth and Welfare of Juvenile African Catfish

Background and Objective: Photoperiod can influence the growth and welfare of Clarias gariepinus. This study aims to investigate the response of African catfish to different photoperiodic regimes with regard to growth performance. Materials and Methods: Clarias gariepinus was reared in triplicate under three photoperiods: 24 hrs total light (24L:0D); 12 hrs of light and 12 hrs of darkness (12L:12D) and 24 hrs of total darkness (24D:0L) fed at 5% body weight. The experiment lasted for 18 weeks. Statistically, data was analyzed using Analysis of Variance and Duncan’s Multiple Range Test was used to separate means. Results: From the statistical analysis, significant differences (p<0.05) were observed in some parameters while others were not significantly different. The 12D:12L photoperiod group showed the highest values for growth, net production value (NPV), gross profit (GP), profit index (PI) and benefit cost ratio (BCR), while those under 24L:0D showed the least values. Levels of cortisol were highest and least in 0D:24L and 12D:12L, respectively. As the number of hours of light exposure increased, glucose level increased. This is shown in 00D:24L having the highest glucose level. Conclusion: The study revealed that the simple, low-cost technique of a 12D:12L photoperiod could be applied by farmers to achieve faster growth in less time in view of maximizing profit.