Some stock parameters of Elops lacerta during estuarine phase of life history

Abstract

Some stock parameters of Elops lacerta in Ogun State coastal estuary, Nigeria were carried out between February and July, 2014. Data were collected on length–weight distribution, sexes, stages of gonad   development, food and feeding habits, growth parameters, length-weight relationship (LWR) and condition   factor for 6 months. Data were analysed using descriptive, parametric test and FiSAT II for fish stock   assessment. Results showed that species length class ranged from 11-12 cm to 32-33 cm, sex ratio, 1.04:1 (male:female), was not significantly (p>0.05) different from the expected 1:1 for natural population. Gonadal examination indicated that the fish stock did not mature in the habitat. E. lacerta was found to forage mostly on diatoms and unidentified fish 1 specimen. Estimates of growth parameters, L∞ = 38.33cm, k = 0.74/yr, ɸ¹ = 3.036/yr and Tmax = 4.05yrs. Parameters of LWR, a = 0.00746 and b = 2.917 (r² = 0.950) were estimated. b was not significantly (p>0.05) different from 3.0 depicting isometric growth pattern. The condition factor ranged between 0.649±0.046 (March) and 1.140±0.021 (July). The study revealed that the habitat provided a good ecosystem to support the fish population. Regulatory policy should therefore be available to ensuring its sustainability and continuous onward recruitment into the marine environment.

Keywords: Elops Lacerta, life history, Ogun State coastal estuary, condition factor, growth parameters