New species of free-living nematodes from Biwa Lake and inflowing stream (Honshu Island, Japan)

Fifty-three species of free-living nematodes were found in the coastal zone of Biwa Lake and an inflowing stream. Eight of them are new. Five new species (Mongolotheristus timoshkini, Daptonema obesus, Tri[dentulus obscurus, T. minor, Monochoides asiaticus) are described and illustrated. Tridentulus obscurus was earlier described from shallow water bodies of the Novaya Zemlya Archipelago as Eunionhystera dispar (Bastian, 1865). Eunionhystera bidenticulata Gagarin, 1997 is transferred to the genus Tridentulus. A key to identifying four valid species of the genus Tridentulus is given.