Two New Species of Chromadorids (Nematoda, Chromadorida) from the Water Bodies of Vietnam

An illustrated description of two new species of free-living marine nematodes from water bodies of Vietnam is given. Dichromadora agilis sp. n. has been found in an artificial reservoir for shrimp cultivation. D. agilis sp. n. morphology is close to D. apapillata Timm, 1961 and D. weddellensis Vermeeren, Vanreusel, Vanhoves, 2004. It differs from both species by the basal bulb structure of pharynx, longer head setae, and structure of gubernaculum. Major morphological traits of valid species of the genus Dichromadora, characterized by absence of supplements in males, are provided. Chromadorina affinis sp. n. was found in small river estuary of Vietnam. Ch. affinis sp. n. is close to Ch. macropunctata (Wieser 1951) and Ch. cervix (Wieser, 1951). It differs from Ch. macropunctata by a shorter tail, shorter head setae, and the presence of precloacal supplements. It differs from Ch. cervix by a comparatively wider body, shorter head setae, and the presence of ocelli. Major morphological traits of valid species of the genus Chromadorina are provided.