Echinoderes ultraabyssalis sp. nov. from the Kuril-Kamchatka Trench – the first hadal representative of the Kinorhyncha (Kinorhyncha: Cyclorhagida)

A new species of echinoderid kinorhynchs, Echinoderes ultraabyssalis sp. nov. collected from oxidized brown clay at the deepest depression of the Kuril-Kamchatka Trench, North-West Pacific, is described and illustrated using light and electron microscopy. This new representative of the largest kinorhynch genus is characterized by the unique set of spines and tubules and can be easily distinguished from other congeners. The first trunk segment...