Echinoderes vulcanicus sp. nov. from the active marine volcano Piip – the first representative of the Kinorhyncha in the Bering Sea (Kinorhyncha: Cyclorhagida)

Abstract

A new species of echinoderid kinorhynchs, Echinoderes vulcanicus sp. nov. collected from detritus washed off deep-water sponges collected at the slope of active marine volcano Piip in the Bering Sea, North-West Pacific, is described and illustrated using light and scanning electron microscopy. This new representative of Echinoderes, the most specious kinorhynch genus, is characterized by a unique set of characters and is easily distinguished from the other congeners. This species is well recognized by the structure of the terminal segment having large, broadly rounded sternal plates prominently extending beyond shorter tergal extensions. Both sternal and tergal plates of this segment have prominent terminal fringe with long and thick tips. The second trunk segment bears a pair of adhesive tubes; trunk segment 5 with pair of tubes in lateroventral position; acicular lateroventral spines on trunk segments 6–9; acicular middorsal spines on trunk segments 4–8; trunk segment 10 with pair of tubules in lateroventral position; males possess three pairs of penile spines. E. vulcanicus sp. nov. constitutes the first kinorhynch species found at the top of the active marine volcano and the first representative of the Kinorhyncha in the Bering Sea.