SIZE AT ONSET OF SEXUAL MATURITY IN CHASMAGNTHUS GRANULATA (DECAPODA, BRACHYURA)

LÓPEZ G, L.S., STELLA V. Y E. RODRIGUEZ

NAUPLIUS

SOCIEDADE BRASILERA DE CARCINOLOGIA

Lugar: RIO GRANDE DO SUL, BRASIL; Año: 1997 vol. 5 p. 65 - 75

0104-6497

The size at maturity of the estuarine crab Chasmagnathus granulata was investigated. The relative growth of morphological characters with reproductive value, in males and females, as well as the gonadal maturity of testes and ovaries at the histological level, were studied. Gonadal maturity, in both sexes, occurs before changes in the relative growth of reproductive characters were noted. The relative growth of the male first pleopod changed upon reaching a carapace width (CW, reference size) of 16.5 mm, while mature testes could be observed at 10.5 mm CW. Spermatozoids were observed in vasa deferentia of males as small as 12.08 mm CW. For females, variations in relative abdominal growth occurred at 22.7 mm CW, while females as small as 19.00 mm CW had mature ovaries. The size of the smallest ovigerous females collected in the field was close to the size of gonadal maturity, but below the 5% critical value of normal size distribution of the ovigerous females. The allometric size of maturity was, in turn, above that critical value.