Length-Weight Relationship and Fecundity of Clarias Gariepinus in a Tropical Reservoir, Southwest, Nigeria

This study considered the length-weight relationship and fecundity of Clarias gariepinus in Ero reservoir, a tropical reservoir in Ekiti, Southwest Nigeria. Four hundred and eighty eight (488) specimens of the fish species were collected during the period of study spanning between April 2003 and March 2005. Gears employed were gillnets, cast nets, basket traps and hook and lines. Standard length ranged between 29.1 and 33.1 cm, while weight ranged from 225.87 to 373.48 g. The linear relationship of length and weight of the C. gariepinus population showed isometric growth pattern with ‘b’ values being higher than 3. Mean fecundity was 769. High positive correlation was recorded between fecundity and standard length (r = 0.71, p<0.05) and also between fecundity and weight (r = 0.874, p<0.05). Keywords: Clarias gariepinus, length-weight relationship, Ero reservoir, Nigeri

Preliminary evaluation of some aspects of the ecology (growth pattern, condition factor and reproductive biology) of African pike, Hepsetus odoe (Bloch 1794), in Lake Eleiyele, Ibadan, Nigeria

Abstract A preliminary investigation of length-weight relationship, condition factor and reproductive ecology of African pike fish, Hepsetus odoe, was conducted between June to August 2010 in Lake Eleiyele. A total of 90 samples of the fish species were caught by fishermen using gill nets. The results obtained showed that fish species had isometric growth pattern (contrary to negative allometry expected) with the growth exponent, b value of 2.64, that is not statistically different from 3 and with high statistical power of 0.866 when tested. The mean condition factor, K, was found to be 2.6, indicating that the fish species were in good condition in the study area. For reproductive biology, mean fecundity and gonadosomatic index were found to be 1349 eggs and 3.53% respectively. This study was necessary to fill the knowledge gap and provide information for management and conservation of the investigated species in the lake system. This study recommended that further research needs to be conducted because the sampling was carried out in the rainy season period and within a quarter of a year