Population dynamics and growth modelling of Oreochromis aureus in the Josefa Ortiz de Domínguez reservoir, Sinaloa, Mexico: Oreochromis aureus growth

Abstract

The tilapia Oreochromis aureus is the main source of income for the fisheries sector in the Josefa Ortiz de Domínguez reservoir, Sinaloa, México. Data that contribute to the pool of biological and fishery information which can be used to lay the groundwork for an appropriate management plan for this species is of extreme importance. Monthly sampling data of the commercial fishery conducted from October 2011 to April 2012 in this reservoir were used to modelling the growth through the Schunte model, and the best sub model (cases) was chosen according to Akaike’s criteria. The size at maturity for females and the selectivity for the total population were estimated with the logistic model. From 1,689 tilapias analyzed the sizes fluctuated from 125-305 mm of total length (TL) for females, and from 125-370 TL for males. The best Shunte’s cases were 2 and 5 according to Akaike’s criteria. The female maturity size calculated was 197 mm TL.  Based on these values for growth, size at maturity and selectivity for the species, it may be deduced that there is some factor that is negatively impacting juvenile and fertile female tilapia at the reservoir.