Advances in Life Sciences 2012, 2(3): 68-74 DOI: 10.5932/j.als.20120203.05 Effect of Season on Catch rate, Diet and Aspects of Reproduction of Clarias gariepinus (Teleostei: Clariidae) in a Tropical Waterfalls Gabriel U. Ikpi 1 , Adetola Jenyo-Oni 2 , Benedict O. Offem 3,* 1 Department of Fisheries and Aquatic Science, Faculty of Agriculture and Forestry, Cross River University Of Technology, Obubra Campus, Cross River State, Nigeria 2 Department of Wildlife and Fisheries Management, Faculty of Agriculture and Forestry, University of Ibadan, Nigeria 3 Department of Fisheries and Aquatic Science, Faculty of Agriculture and Forestry, Cross River University Of Technology, Obubra Campus, Cross River State, Nigeria Abstract The African catfish Clarias gariepinus (Burchell 1822) are highly valued food-fish and are among the dominant fishes of commercial catches in major rivers in Africa. The aim of the present study was to provide data on reproductive biology, diet habits, length–weight relationship and condition factor that can be useful for conservation and propagation of this species. The study was carried out over 24 months in the three reaches of the 200 km- long of Agbokum waterfalls, Nigeria. The influence of season on catch rate, reproduction and diet was determined from catch samples. There was a sig- nificant difference in the catch rate between the dry and wet seasons. Peak catch occurred during the early and late rains. The peak breeding period was June - July. The fish were omnivorous, with trophic flexibility being related to food availability. The condition of the fish was better downstream of the waterfalls than the other two reaches, but declined during dry season and improved during early and late rains. Therefore downstream reaches during wet season are significant in the fisheries studies of waterfalls Keywords Waterfalls, Catch Rate, Fecundity, Diet Habit, Condition Factor, Season 1. Introduction Clarias gariepinus belong to the family Clariidae and occur in most freshwater bodies of South East Asia and Africa where they constitute a significant component of the catches. The highest genetic diversity is found on the African continent where some 14 genera have been reported[1] against two in Southeast Asia. They have high market value in Nigeria and the world at large, and a vital source of vita- mins and protein which are highly digestible[2]. They are very strong and easily adapted to their environment; they are inexpensive in term of the cost of production when cultured. They live in freshwater lakes, rivers, swamps, as well as human-made water bodies, such as ponds or even urban sewer systems[3]. Clarias gariepinus commonly refer to as African Catfish is a large, eel-like usually of dark gray or black coloration on the back, fading to a white belly. It has a slender body, a flat bony head and abroad terminal mouth with four pairs of barbell[4]. In both continents Clarias gariepinus are of great * Corresponding author: benbeff06@yahoo.com (Benedict O. Offem) Published online at http://journal.sapub.org/als Copyright © 2012 Scientific & Academic Publishing. All Rights Reserved economic importance as food fish and vital in the sustain- ability of aquaculture due to their attributes[5] which include; abil ity to withstand handling stress, disease resistance, high growth rate, yield potential, fecundity and palatability[6]. There is acute reduction of these species in inland waters in Nigeria because of the over-exploitative nature of indigenous fishers that destroys the habitat and fisheries resources[7]. Knowledge on their biology is important for rational utili- zation of stock. An effort by the Nigerian government to conserve and propagate these species through fisheries regulation and fish breeding is being hindered because of the little information available on the ecology of these species in Nigerian waters. Most of the research works are limited to the reproductive biology of C. gariepinus[8, 3, 10-13]. No work had been undertaken on the ecological studies of C. gariepinus in Waterfalls. This paper therefore provides in- formation on the ecological influence of season on the dis- tribution catch rate, diet and reproduction of C. gariepinus in waterfalls of Southeastern Nigeria. These data will form the bases for management strategy of this species in waterfalls in Africa. 2. Materials and Methods Study area. The study area is Agbokim Waterfalls in