The first description of kinorhynchs from the Spitsbergen Archipelago (Greenland Sea), with a key to the genus Pycnophyes (Homalorhagida, Kinorhyncha)

Abstract

Two new species of Kinorhyncha, Pycnophyes spitsbergensis and P. mokievskii, are described and illustrated from muddy sediments of the Greenland Sea, from the Isfjord of the West Spitsbergen Island (78°N) at a depth of 6 m. These are the first kinorhynchs described from Spitsbergen, and are the northernmost kinorhynchs found within the Arctic Circle to date. Pycnophyes spitsbergensis and P. mokievskii are the fifth and sixth members of this genus described from Arctic waters. The unique structure of the ventral posteriomesial pachycycli of the 12th segment, rectangular anteromesial ventral pachycycli of the 9th to 12th segments, and ventrolateral cuticular scars on the sternites clearly separate P. spitsbergensis from known congeners. The sympatric species, P. mokievskii, is easily separated on the basis of two closed midventral protrusions with sensory papillae at the posterior end of the body. Pycnophyes greenlandicus Higgins and Kristensen, 1988 from Greenland and P. maximus Reimer, 1963 from northern Europe are similar in size and general morphometric characters to the species described.