Combined Effects of Temperature and Salinity on Larval Development of the Mangrove Crab Parasesarma catenata Ortman, 1897 (Brachyura: Sesarmidae)

Abstract

The larval stages of the mangrove crab Parasesarma catenata were reared in the laboratory from eggs of females collected in the Mgazana estuary, South Africa. Survival and duration of larval stages were tested for the combined effects of temperature and salinity in a factorial design experiment, using three females each with two replicates of 15 larvae per combination. Combinations were made from five temperature (15, 20, 25, 30 and 35 ºC) and four salinity values (15, 25, 35 and 45 ‰). Results were tested by ANOVA and multiple regression was applied to generate contour models by polynomial equation. It was found that P. catenata larvae develop optimally in near to seawater salinity at a temperature of around 25 ºC. These results support the assumption that newly-hatched larvae of this species are exported from the estuarine environment to the sea for development.