The tanaidacean fauna from hydrothermal vents habitats on the Juan de Fuca Ridge, Escabana Trough, Gorda Ridge and from experimental wood deployments, is examined. The material revealed species belonging to the genera; Armaturatanais, Meromonakantha, Neotanais, Pseudotanais, Protanais, Typhlotanais, and an undescribed typhlotanaid genus. The tanaidaceanfauna was almost exclusively dominated by Protanais, which in turn was almost exclusively found on recovered wood blocks. Most species are new to science and the species Armaturatanais trispinipodus n. sp. and Protanais ligniamator n. sp. are described. New information on tanaidacean ontogenetic variation is given for Protanais ligniamator.
Food resource partitioning and competition among alvinellid polychaetes of Juan de Fuca Ridge hydrothermal vents