Bioecological observations on the blue crab Callinectes danae Smith, 1869 ( Crustácea, Portunidae ), in the complex bay and stuarine area of Santos, São Paulo,State, Brazil

Abstract

A total of 6,428 exemplars of Callinectes danae collected from the estuarine-bay complex of Santos, SP, Brazil, from March/1979 to September/1983 was studied through the method described in Santos (1978). Thus, it was estimated that the size of the sexual maturation is 5.5 cm and 6.7 cm (width of carapace) for females and males, respectively. It was observed that the preferred ambient for immature females are low salinity waters (estuary) and for mature females, the saline ones (bay) being the sexual maturation the trigger of the migration of the females to the bay. These females do not return to the estuary. This migratory behavior probably supports the stability of the production of C. danae in the estuary. The male/female relationship obtained for the juveniles (that concentrated in the estuary) was 1:1. Among the adults, males predominated in the estuary (relationship of 2.77:1) and females, in the bay (relationship of 1:2.43). Females with mature eggs occurred through the year in the bay, with greater concentration between September and November. This seems to be the main period of spawning for the species in the area. The statistical mode of width of carapace to females with mature eggs was 6.0 cm, the size of first spawning to those females.