Distribution of the portunid crab Ovalipes punctatus (De Haan) in Algoa Bay and salinity and temperature tolerances of its zoeae

Abstract

The three-spot swimming crab Ovalipes punctatus is commonly found in surf zones off sandy beaches in Algoa Bay. It is exclusively marine and occurs down to a depth of 38 m. Large crabs were found close inshore while smaller crabs were predominantly found in deeper water, suggesting that settlement mainly occurs offshore in water 25 - 38 m deep. Gravid females were found closer inshore in shallow water. The zoeae could not tolerate high temperatures (>27, 5 �C) or low salinities (>15�). The optimal temperatures and salinities for survival of the zoeae were 15-22 �C and 34-35� respectively.