A new species of the Cymbasoma longispinosum species-group (Copepoda, Monstrilloida) from the northern South China Sea

A new monstrilloid copepod species, Cymbasoma stricturum sp. nov., is described and illustrated on the basis of adult females from the Pearl River estuary, northern South China Sea. The new species is closest to C. morii Sekiguchi, 1982, C. sinopense Üstün, Terbiyik & Suárez-Morales, 2014, and C. jinigudira Suárez-Morales & McKinnon, 2016, but it can be distinguished by a combination of characters including strongly protuberant, straight oral papilla; a cephalothorax that is distinctly constricted at the anterior two-fifths in both dorsal and lateral views; and two pairs of well-developed nipple-like processes on anterior dorsal surface, among other diagnostic traits.

This is the ninth nominal species known in the Cymbasoma longispinosum species-group. We provide an updated dichotomous key for females and a revised worldwide distribution map of the species-group.