Temporal variation, growth and natural mortality of two species of mojarras (Perciformes: Gerreidae) from a tropical coastal lagoon: La Carbonera, Yucatan, Mexico

This study reports seasonal variation, growth parameters and natural mortality for Eucinostomus gula and Eucinostomus argenteus inhabiting La Carbonera, a tropical coastal lagoon on the northwestern coast of the Yucatan Peninsula, Mexico. Specimens were collected between April 2009 and March 2010. A total of 2700 organisms of E. gula (> 80% in rainy season ) and 1577 organisms of E. argenteus (>50% in dry season) were collected during the study period. Length-weight relationship (LWR) obtained was W = 8.323E-03 Lt2.92 in E. argenteus and W = 7.314E-03  Lt2.92 in E. gula.  Growth parameters of von Bertalanffy growth function (VBGF) by length frequency analysis were in E. argenteus: L∞ = 13.65 cm,  k = 0.54 year-1 and t0 = - 0.37 years; and in E. gula: L∞ = 12.60 cm, k = 0.68 year-1 and t0 = - 0.28 years. Additionally, estimated natural mortality in E. gula was 1.50 year-1 and in E. argenteus was 1.9 year-1. This study presents the first estimation for both species of model parameters, growth performance index and mortality for the Yucatan Peninsula, which is relevant for the proper implementation of conservation measures for E. gula and E. argenteus in an important coastal zone of the Yucatan Peninsula.