3 NEW SPECIES OF POGONOPHORA, INCLUDING 2 VESTIMENTIFERANS, FROM HYDROTHERMAL SITES IN THE LAU BACK-ARC BASIN (SOUTHWEST PACIFIC-OCEAN)

Hydrothermal fields on the Valu Fa Ridge at about 22-degrees-32'S, 176-degrees-43'W, were explored by the submersible Nautile during the French BIOLAU expedition in 1989. Pogonophorans were found during six of the 12 dives, at depths of about 1900 m. They were exposed to the influence of hydrothermal fluids but probably did not experience elevated temperatures. One new species of sediment-living perviate pogonophore was collected. Two new obturate pogonophores (vestimentiferans), one belonging to a new family, lived attached to hard substrata. There is a complete faunistic separation of the Lau Basin vestimentiferans from the eastern Pacific vent faunas. Families as well as genera are different, and the Lau species appear to have more in common with cold seep faunas.