Population structure of caitipa mojarra (Diapterus rhombeus) in an estuarine system of southeastern Brazil

Abstract

Santos estuary suffers anthropic influence through various activities, including fisheries. Caitipa mojarra (Diapterus rhombeus) is among the exploited resources of the region and, despite its importance, it has not been well studied yet. The main goal of this study was to analyze the population structure of this species regarding gonadal development, age and growth. For the analysis of gonadal development, samplings were carried out between November 2008 and August 2011, gathering a total of 6,639 individuals. The age and growth parameters were analyzed from a data base of the species, which contained information from samplings from October 2007 to September 2011. Most of the specimens caught (71.93%) was considered juvenile and only 0.68% were spawning. From gonadal maturity, sexual proportion and length classes of the individuals, it could be seen that this species does not spawn within Santos estuary. The growth parameters estimates were L∞ of 262.5 mm, k = 0.24/year and longevity of 12.48 years.