TWO NEW FOR SCIENCE SPECIES OF FREE-LIVING NEMATODES OF FAMILY DESMODORIDAE FILIPJEV, 1922 (NEMATODA, DESMODORIDA) FROM CORAL REEFS IN VIETNAM

Two new nematode species of the family Desmodoridae Filipjev, 1922, found in coral reefs in Vietnam, are described and illustrated. Onyx vulgaris sp. n. in body size and spicules length is close to D. disparamphis Tchesunov, Jeong, Lee, 2022 and O. orientalis Nguyen Dinh Tu et al., 2011. It differs from first species by the comparatively shorter and less slender tail, different form of terminal bulb of pharynx, different form of amphidial fovea and differs form of precloacal supplements in males. It differs from second species by the longer inner labial setae, shorter terminal bulb of pharynx, close to anterior body end located vulva and longer gubernaculum. Desmodora coralis sp. n. close to D. scaldensis de Man, 1889, D. macramphis S. Stekhoven, 1950 and D. nini (Inglis, 1963) in body size and absence of precloacal supplements in males and differs from all three species by the thinner body and presence of tubercle with pore on ventral side of tail in males.