TAXONOMY AND ECOLOGY OF 2 ENDEMIC FRESH-WATER CRABS FROM WESTERN JAMAICA WITH THE DESCRIPTION OF A NEW SESARMA SPECIES (BRACHYURA, GRAPSIDAE, SESARMINAE)

The type series of the Jamaican grapsid crab Sesarma windsor Turkay an d Diesel, 1994, was re-examined and found to consist of two distinct f orms. The holotype represented a form so far only recorded from a fres hwater cave in western Jamaica. The other form inhabits burrows in the banks of mountain creeks in western Jamaica and is assigned to a new species, Sesarma fossarum sp. n. Both species are fully described and morphological differences partly interpreted as adaptations to the hab itats where they occur. The new species and S. bidentatum Benedict, 18 92, both from mountain creeks, closely resemble the cavernicolous S. w indsor which suggests a fairly recent invasion of the cave habitat by the latter.