Research Article: Age, growth and mortality of white grouper Epinephelus aeneus from the Senegalese coast (West Africa)

The objective of the study is to describe the length-frequency distribution, (۲) to estimate the growth parameters by counting growth bands deposited on whole otolith (۳) to determine the white grouper natural mortality. White grouper (Epinephelus aeneus) sampled from Soumbédioune, Mbour, and Joal along the southwestern coast of Senegal in ۲۰۲۰ (n = ۹۷۳) were aged by counting opaque bands on whole sagittal otoliths. Total length (TL) ranged from ۱۷۹.۰ to ۹۴۸.۰ mm with an average of ۴۲۲.۴۸±۱۳۳.۷۹ mm. Analysis of otolith edge type (opaque or translucent) revealed that annuli formed in July-January with a peak in November. White grouper was aged up to ۸ years, and the largest fish measured ۹۴۸ mm in total length (TL). The von Bertalanffy function provided the following parameters: L∞=۱۰۴۲ mm, K=۰.۱۳ year-۱ and t۰= -۱.۴۸ year. Natural mortality (M) estimated by Hewitt & Hoenig’s longevity-based method which integrates all ages was ۰.۵۰. Because this is a species with a low growth rate, the population of E. aeneus in Senegalese coast requires prudent management. Furthermore, fishery managers need to consider as part of any harvest strategy for these fish the preservation of significant levels of the spawning stock by reducing the numbers of juvenile fish captured in the shrimp trawls and for sale in the market.

کلیدواژه ها:

Epinephelus aeneus ، Otolith ، Age ، Growth ، Mortality ، Senegal coast