Estrutura populacional e biologia reprodutiva de Callinectes bocourti A. Milne-Edwards, 1879, em estuários da Amazônia Brasileira.

Abstract

The estuary is a semienclosed body of water with free connection to the open sea, recognized as a spawning and breeding ground for several species, responding, directly or indirectly, to the sustainability of some species of interest to fishing. The samples were collected in the estuaries of the Municipalities of Bragança, Salinópolis and Vigia, with monthly collections carried out in the years 2011 to 2013. The crabs collected were transported to the analysis in the Crustaceans Laboratory. The fishing equipment used for the collection was a manual drag. The seasonal period was defined with INMET data (Station: Belém, Soure and Tracuateua). Specimens were identified, sexing and biometry. The information was annotated and treated with descriptive statistics to obtain means and 95% confidence intervals and analysis of variance (ANOVA) considering categorical variables, location, sex and station. The Tukey post hoc test was used to identify differences in multiple comparisons through the statistical package STATSOFT 7.0. The sex ratio was calculated among the carapace width classes, using the chi-square test (χ2). The L50 was calculated using Microsoft "Excell" software. We also analyzed: stages of gonadal maturation; reproductive period; relative condition factor (Kr) and fecundity. Of the 1.347 individuals collected, 448 were females and 899 males. There were more males compared to females, in all months only in the Municipality of Bragança. Males were larger and heavier than females. Salinópolis presented larger and heavier individuals compared to Vigia and Bragança. For the sex ratio, males were more abundant than females, where the proportion differed from one male to each female captured. There were 291 specimens identified. The L50 for females was estimated to be 7,41 cm wide for the carapace. All the gonadal stages were found throughout the period for Bragança and Salinópolis, except in Vigia, where the Estádio In development was not found. The largest averages of carapace width were obtained in the stages: In development and Advanced for Bragança and Salinópolis and in the Intermediate and Advanced stages for Vigia. The presence of different stages of gonadal maturation indicates that the reproductive cycle can be completed in this region, indicating continuous reproductive activity. Three spawning peaks were evident over the same period. Ovigerous females were found only in Bragança and Salinópolis, with a total of six individuals. The estimated absolute mean fecundity was 498.270 eggs, while the relative mean fecundity was 9.580,05 eggs / g. The diameter of the egg was estimated varying from 0,20 mm to 0,26 mm.