A new genus and species of alvinocaridid shrimp (Crustacea : Decapoda : Caridea) from hydrothermal vents on the North Fiji and Lau Basins, south-western Pacific

Nautilocaris saintlaurentae gen. nov., sp. nov., is described and illustrated from hydrothermal vents in the North Fiji Basin and Lau Basin in the south-western Paci¢c. This new taxon is assigned to the Alvinocarididae. It has a well-developed, dorsally dentate rostrum, carapace with pterygostomian spine present, eye broadly fused mesially, epipod^setobranch complex present above pereopods, and appendix internae on second to fourth pleopods greatly reduced.This combination of characters places it in an intermediate position between a group of species in the genus Alvinocaris with well developed, dorsally dentate rostrum, carapace with pterygostomian spine present, eyes narrowly fused mesially, epipod^setobranch complex absent and well-developed appendices internae on second to fourth pleopods, and Mirocaris fortunata with rostrum unarmed, carapace with rounded pterygostomian angle, eye broadly fused mesially, epipod^setobranch complex present above pereopods and appendices internae on second to fourth pleopods greatly reduced. The habitat of the new species is brie£y described.