A new species of Halicyclops (Copepoda, Cyclopoida, Cyclopidae) from cenotes of the Yucatan Peninsula, Mexico, with an identification key for the species of the genus from the Caribbean region and adjacent areas

Halicyclops cenoticola sp. nov. is described from cenotes of the Yucatan Pe ninsula, Mexico. The new species shares exclusively with H. caridophilus an d H. tetracanthus the presence of 2 inner setae on the leg 5 exopod in the males. As far as is known, the new species is distinguished from all its co ngeners in having the dorsal caudal seta as long as the outer middle caudal seta; legs 2 and 3 are dimorphic concerning the structure of the 3 inner s etae on the. terminal endopodal segment; and leg 6 of both the male and fem ale consists of only 2 elements. An identification key for the Halicyclops species known from the Caribbean Region, the Gulf uf Mexico. Bermuda, and the coast of French Guiana is incl uded.