REPRODUCTIVE ANALYSES OF THE SWIMMING CRAB ACHELOUS SPINICARPUS (STIMPSON, 1871) (CRUSTACEA: DECAPODA: PORTUNOIDEA) ON THE NORTHERN COAST OF SÃO PAULO, BRAZIL

Resumen

ABSTRACT: The swimming crab Achelous spinicarpus can be considered an ‘indicator’ of cold-water environmental conditions in the northern coast of Sao Paulo, Brazil. In order to improve our understanding about this species, we examined size at sexual maturity, breeding period, and recruitment events of A. spinicarpus in the region. Swimming crabs were sampled by monthly trawling at seven depths in two locations (Ubatuba and Caraguatatuba) from July 2001 to June 2003. A total of 1057 specimens of A. spinicarpus were collected in Ubatuba (598 males and 459 females), from which only 15 females were ovigerous. Size at sexual maturity was estimated to be 24.2 and 23.8 mm carapace width (CW) in males and females, respectively. In Caraguatatuba, 5112 individuals were collected (3138 males and 1974 females), from which only 29 females were ovigerous. Size at sexual maturity was estimated to be 23.7 and 23.5 mm CW in males and females, respectively. Ovigerous females and juvenile recruitment occurred mostly during spring and summer seasons. Size at sexual maturity in A. spinicarpus differ from that previously reported for the species, suggesting certain reproductive plasticity.

Keywords: Brachyura, water mass, reproduction, recruitment, sexual maturity