A new genus of free-living nematodes (Enoplida: Enchelidiidae) from the South China Sea

A new genus, Polygastrophoides gen. nov., is established with the type species Polygastrophoides elegans gen. nov. and sp. nov. from the South China Sea. Polygastrophoides gen. nov. is characterized by having a strongly attenuated anterior end; six internal labial papillae, six shorter outer labial setae and four longer cephalic setae arranged in one circle; buccal cavity divided into 2-3 chambers; ocelli present; pharynx lacking muscular bulbs; spicules elongated; gubernaculum without apophysis; papilliform precloacal supplements present; tail conico-cylindrical with terminal spinneret. It is different from Polygastrophora by lacking of multiple pharyngeal terminal bulbs. The new genus differs from Abelbolla by the form of precloacal supplements and the absence of gubernaculum apophysis. Abelbolla species having two winged precloacal supplements and gubernaculum with dorsal apophysis. This genus is different from Symplocostoma by male with typical chambered buccal cavity of the Enchelidiidae. In Symplocostoma, buccal cavity sexually dimorphism, male buccal cavity absent, female buccal cavity divided into several chambers and the posterior chamber not continued down the pharyngeal lumen.