Age And Growth Of An Ecotype Cichlid “Wesafu” In Epe Lagoon, Lagos, Nigeria

Abstract

A sample of 150 specimens of “Wesafu” in the size range of 78mm and 414mm were collected from Epe Lagoon. The period of collection spanned August to November 2003 and April to Ma y 2004 for age and growth pattern determination of this Ecotype Cichlid of Epe Lagoon. 900 scales were examined and another 232 rejected/discarded because they were regenerated or irregular. Growth rings were counted and scale radii measured. The study showed a mean range of observed lengths to be 181±12.5; 265 ± 11.6; 305 ± 1.6 and 337 ± 3.4 for the successive years of growth. The most rapid growth in length occurred during the first year in life [181mm, (+1yr.)] thereafter decrease to only 32mm in the fourth year (+4yr.). The T-test suggests that there was no significant difference between mean back-calculated body length of male and female samples for age 1+ to 3+. However, in the age group 4+, male specimens were significantly larger than the female. The fact that the fish is highly demanded and commands premium price may result in over exploitation. This explain why only 5 of the 150 specimens were of the age 4+, representing only 3.33% of total specimens which raises serious conservation question and the need for domestication and aquaculture of this highly valued fish in Lagos, Nigeria.

Keywords: Age and Growth, Ecotype Cichlid, Epe-Lagoon, Nigeria

Global Journal of Agricultural Sciences Vol. 7 (1) 2008: pp. 105-109