A New Species of Deep-sea Nematode, Micoletzkyia mawatarii sp. nov. (Nematoda: Enoplida: Phanodermatidae) from Northern Japan

A new species of free-living marine nematode, belonging to the genus Micoletzkyia Ditlevsen, 1926 (Phanodermatidae Filipjev, 1927), is described from the deep sea off the coast of Hokkaido, northern Japan. Micoletzkyia mawatarii sp. nov. resembles M. magna Vitiello, 1970 and M. longispicula Huang and Cheng, 2012 in the shape of the tail and gubernaculum, but differs from the former in body width and in length of the cephalic setae, and from the latter in body length, proportional length of the tail, position of the nerve ring, and shape of the precloacal supplement. Micoletzkyia mawatarii sp. nov. also resembles M. parelegans Allgen, 1954 in its large body size, but differs from it in esophagus length, shape of the gubernaculum, size and position of the precloacal supplement, and in having a longer tail.