Dimorphostylis pilocorpus sp. nov. (Crustacea, Cumacea, Diastylidae), a new cumacean from Korean waters

Abstract

A new species of Cumacea belonging to the genus Dimorphostylis Zimmer was collected from the Dokdo and Ulleung Islands in the East Sea of Korea. The new species, Dimorphostylis pilocorpus sp. nov., can be distinguished from all other Dimorphostylis species by the combination of the body surface covered with numerous slender simple setae; carapace with one transverse, a pair of frontal, and three pairs of oblique ridges; three pairs of oblique ridges connected on a submedian carina; telson of the female with 1 pair of short simple and 1 short, stout simple seta centrally; 1 pair of stout simple and 3 pairs of short simple setae on the post-anal section; pleonite 5 of male with 1 spiniform seta on the ventral margin; post-anal section with 2 pairs of stout simple setae bearing a single subterminal setule on both sides; terminal margin with 3 stout simple setae; and a central seta slightly longer than the outer pair of setae. Full illustrations of the new species, including the mouthparts, are given in this paper. A key to the Korean species of Dimorphostylis is also provided.