Growth Parameters and Alliance Between Selected Morphometric Features of Schilbe mystus in Asejire Reservoir, Nigeria

Background and Objective: Captive rearing of fish requires up-to-date information on key biological attributes such as growth parameters, size structure and other morphometric indices. This study thus investigates the morphometric characteristics of some key aging structures and growth parameters of Schilbe mystusin Asejire Reservoir, Nigeria. Materials and Methods: The 306 samples were obtained and weighed. Total length (TL), cleithra length (CL) and otolith height (OH) were measured. Length at first maturity (L_m), optimum length (L_opt), asymptotic length (L∞), growth co-efficient (K) and overall growth performance index (Ø) for each sex were calculated using von Bertalanffy growth model. Data obtained were analyzed using descriptive statistics, chi-square and multiple linear regression. All statistical analyses were considered at a significant level of 5% (p<0.05). Results: The TL of the fish ranged from 11.5-22.0 cm and the body weight ranged from 8.00-74.00 g. The Log W = -1.5836+2.7015 log L described the length-weight relationship. The fish exhibited negative allometric growth (K = 1.195±0.19) while length frequency distribution showed one modal peak (14-17 cm). The growth parameters were: L_m = 12.5, 14.1 cm, L_opt = 12.3, 14.1, L∞ = 20.4, 23.2 cm, K = 0.26, 0.05 and Ø = 2.03, 1.43 for male and female, respectively. The regression equation describes the relationship between weight, fish length and otolith, opercula and cleithra dimensions of fish. Conclusion: The study suggested that otolith dimensions’ increase as fish length increases and therefore, otolith growth correlated with fish growth. The female S. mystus grows bigger and are more preponderance in Asejire Reservoir than male.