NEW SPECIES OF ALVINELLIDAE (POLYCHAETA) FROM THE NORTH FIJI BACK-ARCBASIN HYDROTHERMAL VENTS (SOUTHWESTERN PACIFIC)

The polychaete family Alvinellidae Desbruyeres & Laubier, 1986 compris es two genera, Alvinella and Paralvinella, and ten species or subspeci es. All species are strictly associated with hydrothermal vents in the Pacific Ocean. The genus Paralvinella includes eight species or sub-s pecies, plus one additional new species presently being described from North East Pacific hydrothermal fields. In 1989, the French research submersible Nautile had 12 successful dives in the North Fiji back-arc Basin and explored two active hydrothermal vents. Numerous specimens of two additional new species of the genus Paralvinella were collected using the manipulator of the submersible. Paralvinella unidentata, ne w species, exhibits several features that lead us to erect three diffe rent subgenera, Paralvinella s. s., Miralvinella, new subgenus and Nau talvinella, new subgenus, within the genus Paralvinella. This species lives within the anhydrite mass, very close to hot fluid openings. The second new species, P. fijiensis, found in the anhydrite mass, but al so on basaltic rocks, is closely related to P. grasslei, the type spec ies, and to P. palmiformis.