The objective of this work was to get some knowledge about the Guaia stone crab reproduction. The sampling was monthly obtained in the intertidal zone at the Ibicuí Rock Beach. The 638 crabs were collected from August, 1995 to March, 1997. In this total amount 293 were males and 345 (41 ovigerous crabs) were female crabs. Biometrical data informing the total width and length were taken, and gonadal stage was checked macroscopically. The total male width range was between 7.9 to 67.1 mm, while in the female crabs it was between 4.4 to 79.3 mm. The female ones were bigger than the male ones. The ovigerous female crabs were found mainly on Spring and Summer and it probably indicates the reproduction season. The carapace width range of the ovigerous female crabs was about 38.0 and 77.0 mm. The individual fecundity was determined on the number of eggs laid, which were dissociated by means of sodium hipoclorito. The number of eggs laid was about 12,800 and 212,000, according to the female size and the average number of the eggs was 98,800. They were round in shape and their size varied between 0.31 and 0.44 mm. Their average size was 0.37 mm. The five female gonadal stages were determined by the color and the width of the gonads. The estimated mean size of first sexual maturity was 37.8 mm carapace width for female.
Decapoda; Xanthidae; Menippe nodifrons; reproduction; stone crab; Sepetiba Bay