Crescimento em Goniopsis cruentata (Latreille) (Crustacea, Brachyura, Grapsidae) em laboratório

Abstract

The growth of the crab Goniospis cruentata (Latreille. 1803), was studied in the laboratory, through of the molt increment and intermolt period. A total of 86 crabs (48 males and 38 females) were collected in the ltacuruca's Mangrove in Mangaratiba's county. Rio de Janeiro. The crabs were maintened in the laboratory in four 1000 l tanks, with continuous water circulation during fifteen months. They were fed each two days with pieces of fish and fruits. The crabs varied in size from 19.3 to 56.0 mm in males and 23.3 to 48.8 mm in females. The males presented until four molts during the experiment and the females until six molts. The molts oceurred during ali the months. The mean percentage of molt increment was 6.1 ± 2.7%, for both sexes and it decreased with the animal growth. The relation between the molt increment and the carapace width can be expressed by the equation IM = -0.32LC + 18.26 (r = -0.82). This relation didn't show any significative difference between the sexes. The mean intermolt period was of 87.6 + 37.3 days in male crabs and 97.3 ± 27.6 days in females. The growth was contiguous, through successive molts, although the increment was reduced with animal size. The intermolt period was proportional to the animal size increase, however males with autotomy of limbs had the intermolt period reduced.