Fig. 1

Map of SW-pacific region, Alviniconcha species records and Fatu Kapa vent-field study sites. Photo of habitat taken in northern area of Fati Ufu during cruise. The current distribution records for the five Pacific species indicate that only A. kojimai and A. boucheti are found together with any regularity. The distribution of the sixth species, A. marisindica, is restricted to sites on the Central Indian Ocean Ridge (not shown). Image credits: Globe Amrita Carroll; Fatu Kapa Map Futuna 3 cruise, AUV AsterX; Fati Ufu site photo Futuna 3 cruise, HOV Nautile