Population biology and diet of Callinectes sapidus (Decapoda, Portunidae) in Saco da Fazenda, Itajaí­­, Santa Catarina, Brazil

Abstract

The Callinectes genus has constant presence in extractive activities carried out by coastal communities. This study aimed to provide basic information about the population biology of C. sapidus and his diet in Saco da Fazenda (Itajaí­­/SC). The size at first maturity was estimated at 10.8cm (females) and as 8,8cm (males) in total carapace width. The CPUE had the lowest values in spring and the highest in autumn. For the period 2002-2003 the difference between the number of males and females was not significant, with a ratio of 0.84. As for the periods 2003-2004 (ratio=0.75) and 2004-2005 (ratio=1.37), the difference between the number of males and females was significantly. The highest monthly rates of biomass were recorded in the months of April, May, June and July. For the diet analyses were analyzed 254 individuals (120 males and 134 females). The X² test analysis applied to the proportion of the sexes showed no significant difference. The majority of males (80%) and females (78.36%) presented the stomach with content. It was possible to identify 12 dietary items, and the most important are those of animal origin. The vegetable items represent a secondary role in the diet of blue crab.