The Osmoregulatory Ability of Three Grapsoid Crab Species in Relation to Their Penetration of an Estuarine System

Abstract

The osmoregulatory abilities of the grapsoid crabs Cyclograpsus punctata*, Sesarma catenata andSesarma eulimene were studied comparatively in an attempt to explain, at least in part, their distribution in estuaries. Both survival and haemorymph osmotic pressure were used as indices of hyperosmotic regulatory ability.