Proximate compositions and length-weight relationships of hybrid catfish, Clarias gariepinus (♂) X Heterobranchus bidorsalis (♀) under various densities

Abstract

The study evaluated proximate compositions, length-weight relationships, condition factor and the survival rates of hybrid catfish, Clarobranchus (Clarias gariepinus (male) X Heterobranchus bidorsalis (female) reared at different densities in tarpaulin tanks. Fish were stocked at densities of 25, 50, 75 and 100fish/m³. Each treatment was replicated three times. Fish were fed with commercial catfish feed (45% crude protein) at 5% body weight for 84 days. Length and weight data collected were analyzed with FISAT software using the ELEFAN package to estimate relationship in body parameters. The mean exponent (b) for total length was 3.07 for fish reared at 75fish/m³. This showed positive allometric function, indicating that the species gets plumper as it grows larger. The regression line indicated a significant relationship (r = 0.9112; p < 0.05) with the equation W = 5.3783L3.0700. This showed that there was a high and significant correlation between the various total length and weight of Clarobranchus. Fish condition was best at 75fish/m³ density. There were no variations (p<0.05) in fish survival rates and whole body compositions. The results suggested that 75fish/m³ provided optimum environment for rearing Clarobranchus.

Keywords: Hybrid, catfish, condition factor, survival, nutrient values