TROGLOCYCLOPS-JANSTOCKI, NEW GENUS, NEW SPECIES, A VERY PRIMITIVE CYCLOPID (COPEPODA, CYCLOPOIDA) FROM AN ANCHIALINE CAVE IN THE BAHAMAS

Troglocyclops janstocki is proposed to accommodate cyclopids from Hatc het Bay Cave, Eleuthera Island, Bahamas. The species is the most primi tive member of the Halicyclopinae because of the presence of 15-segmen ted antennules, mandibular palp reduced to 3 setae, one of them quite long and plumose, a bisegmented maxillary endopodite, and 3 segments i n the maxilliped endopodite. These copepods possess the first pediger still distinct, being partially enclosed dorsally and laterally by a c arapace-like extension of the posterior margin of the dorsal cephalic shield. This latter character represents a plesiomorphic state shared with the primitive cyclopinids and, within the Cyclopidae, only with t he Euryteinae. The new taxon is the only known species of Halicyclopin ae having two apical spines on the terminal segment of the exopodite o f legs 2 to 4, and the intercoxal sclerites of the legs 1 and 2 sexual ly dimorphic. The phylogenetic importance of each of these characters is discussed.