Length-weight relationship and condition factor of Clarias gariepinus and Oreochromis niloticus of Wudil river, Kano, Nigeria

The length-weight relationship and condition factor of Clarias gariepinus and Oreochromis niloticus from four study sites (Marmara, Ruwan Jaki, Kogin Mada, and Ruwan Yan akuya sites respectively) in Wudil River, Kano State Nigeria was evaluated over a period of four weeks in December 2010. A total of 120 mature fish samples which were caught during the study period using drag net and traps, were immediately immersed in 10% formalin and transported to laboratory. The growth coefficient (b) obtained of the two fish species ranged from 0.1441 to 0.8058 for Oreochromis niloticus, and from 0.1173 to 0.5457 for Clarias gariepinus. The ‘b’ differed significantly (p < 0.05) from 3, indicating negative allometric growth for all fish species. The condition factor (K) ranged from 0.516 (Clarias gariepinus) from Marmara site, to 1.809 (Oreochromis niloticus) from Kogin Mada sampling site. The condition factors of all fish species sampled fall outside the range recommended as suitable for matured fresh water fish species in the tropics. Key words: length-weight relationship, condition factor, Clarias gariepinus, Oreochromis niloticus, Wudil Rive