DISCOVERY OF HYDROTHERMAL VENT TANTULOCARIDA ON A NEW GENUS OF ARGESTIDAE (COPEPODA, HARPACTICOIDA)

Preliminary investigations of hydrothermal vent harpacticoids from the Galapagos Rift resulted in the discovery of a new genus and species o f Tantulocarida. Rimitantulus hirsutus gen. et sp. nov. is described o n the basis of the tantulus larva and the male at an early stage of de velopment. It is the first record of the subclass from hydrothermal ve nt habitats and is placed in the Basipodellidae which exclusively util ize copepods as hosts. The harpacticoid host Argestoides prehensilis g en. et sp. nov., which is known only from the male, shows affinities w ith both the Ameiridae and Argestidae and is placed genus incertae sed is in the latter primarily on account of the complete lack of sexual d imorphism on the swimming legs.