New data of three rare belondirid species (Nematoda, Dorylaimida, Belondiridae) from Vietnam, with the first record and description of the male of Oxybelondira paraperplexa Ahmad & Jairajpuri, 1979

Three rare nematode species of the family Belondiridae, originally described from and only known to occur in India are recorded for the first time in Vietnam: Axonchium thoubalicum, Belondira murtazai and Oxybelondira paraperplexa. It is the first report of these three genera in this country. The three species are described, including new morphological data, morphometrics and light microscope pictures. The male of O. paraperplexa is collected and described for the first time. It is characterized by its 1.54 mm long body, ad-cloacal pair of genital papillae situated at 9.0 µm from the cloacal aperture, only one ventromedian supplement located at 15 µm from the ad-cloacal pair within the range of spicules, spicules slightly curved ventrad and 42 µm long (7 times as long as wide and 2 times as long as cloacal body diameter), and tail 100 µm long (c = 15, c’ = 5) and similar to that of the female.