Fiddler Crabs of Jamaica (Decapoda, Brachyura, Ocypodidae, Genus Uca)

Review of recent collections and older material in the U.S. National Museum of Natural History and the Academy of Natural Sciences of Philadelphia has confirmed the occurrence of six species of fiddler crabs on the island of Jamaica. The discovery of a colony of Uca major in Kingston Harbor has suggested that it was this species rather than the South American form, U. m. maracoani, that formed the basis of a disputed 18th-century identification by Sir Hans Sloane. At the same time another South American species, U. cumulanta, was found to be well represented on the mud flats around Kingston Harbor. The remaining four species are typical of the Caribbean. U. rapax and U. t. thayeri occur in muds associated with mangrove swamps, U. leptodactyla was found on sand, and U. burgersi occupied habitats on both sandy and muddy substrates ranging in salinity from brackish to seasonally hypersaline. U. v. vocator has yet to be reported from Jamaica although it is known from estuaries and mud flats on other islands of the Caribbean. Evidence of female reproductive activity was found in samples of all species, except U. rapax and U. burgersi, collected one to three days before new moon in late March, 1982. Past habitats of fiddler crabs in Kingston Harbor have been extensively modified by pollution, dredging, and filling. A growing body of literature has demonstrated the sensitivity of fiddler crabs to such environmental stresses and pointed to the usefulness of the animals as bioindicators of alterations of local intertidal habitats.