SOMATIC GROWTH IN JUVENILES OF THE ESTUARINE CRAB CHASMAGNATHUS GRANULATA DANA 1851 (BRACHYURA, GRAPSIDAE) UNDER LABORATORY CONDITIONS

LÓPEZ G. L.S. Y E.M. RODRIGUEZ

REVISTA DE INVESTIGACIONES MARINAS

Lugar: VALPARAISO, CHILE; Año: 1998 vol. 26 p. 127 - 135

0252-1962

Male and female juvenile crab of the species Chasmagnathus granulata were collected in Samborombón Bay (Argentina), on October 1994 and February 1995; these dates correspond to the beginning and the end of the reproductive period of the species, respectively. No differences in the initial size (measured as carapace width, CW) existed between both clutches. Each clutch of juveniles was observed during 1-year period, recording the percentage of molted crabs, intermolt period and percentual increment of size after each molting. At the end of the observation period, males and females from the October clutch reached the size of sexual maturity, while crabs of the remaining clutch did not. This difference was due to the higher increment in size of the October crabs at the third and fourth molts, compared to the February ones. Such difference seems to be related to an increase in reproductive effort during the breeding season, once the sexual maturity was attained.