Two New Species of Free-Living Nematode (Desmodoridae, Namatoda) from Mangrove Wetlands of China

Two new species of free-living nematode, Metachromadora parobscura sp. nov. and Molgolaimus longicaudatus sp. nov., from mangrove wetlands of Beihai, Guangxi province in China, are described. Metachromadora parobscura sp. nov. is characterized by eight longitudinal rows of somatic setae arranged from the posterior part of the body, loop-shaped amphidial foveae with an open top and double contours, pharynx with bipartite cuticularized internal cavity, spicules with well-developed capitulum, gubernaculum extended ventrally to support spicule, 6-8 precloacal tubular supplements, and short, conical tail with two protuberances. Molgolaimus longicaudatus sp. nov. is characterized by short cephalic setae, relatively small amphidial fovea, ventrally bent spicules with pronounced hamose curved proximal terminus, two undulate precloacal supplements, and relatively long conico-cylindrical tail. Nearly full-length SSU sequences of the two species were provided, and phylogenetic tree based on maximum likelihood analyses supported the taxonomic position of the two new species. Combined use of traditional morphology-based taxonomy and molecular technology would be a good choice for identification of free-living nematodes.