Marine Gastrotricha of the Caribbean Sea: a review and new descriptions

The tropical northwest Atlantic (TNWA) is one of the world's most understudied areas with respect to meiofauna, microscopic metazoa of the benthos. It includes five ecoregions: the Gulf of Mexico, the Florida Keys, the Bahamian, the Lesser Antilles, and the central Caribbean. The marine Gastrotricha of the Gulf of Mexico are the best known and probably have the most in common with other non-Caribbean localities. Contributions here are made to three of the remaining four ecoregions, with eight species (of which two are new: Chaetonotus semihamus n. sp. and Heterolepidoderma baium n. sp.) being added to the Florida Keys region, four species (of which three are new: Mesodasys saddlebackensis n. sp., Macrodasys gylius n. sp. and Crasiella skaia n. sp.) added to the Bahamian region from Andros Island, and four species (of which three are new: Chaetonotus elachysomus n. sp., Chaetonotus eratus n. sp. and Chaetonotus polyhybus n. sp.) added to the central Caribbean region from the U.S. Virgin Islands. Other species described from Andros Island, Bahamas, include: Macrodasys achradocytalis Evans, 1994, Macrodasys meristocytalis Evans, 1994 and Thaumastoderma thysanogaster Boaden, 1965, and from the U.S. Virgin Islands: Aspidiophorus paramediterraneus Hummon, 1974 and Chaetonotus dispar Wilke, 1954. These data raise the number of species known from the TNWA (omitting the Gulf of Mexico) to 47 (with 27 being described from the quadri-regional area).