Thalassoalaimus de Man, 1893

Martelli, Antonela, Russo, Virginia Lo, Villares, Gabriela & Pastor De Ward, Catalina T., 2017, Two new species of free-living marine nematodes of the family Oxystominidae Chitwood, 1935 (Enoplida) with a review of the genus Thalassoalaimus de Man, 1893 from the Argentine coast, Zootaxa 4250 (4), pp. 347-357 : 349

Thalassoalaimus de Man, 1893 , emended diagnosis

Oxystominidae , Oxystomininae . Labial sensilla setiform, in circles of six inner and four or six outer on the anterior end. A circle of four cephalic setae more posteriorly. Amphideal fovea large and pocket-shaped. Males usually have papilliform precloacal supplements. Tail conical or conico-cylindrical. Thick cuticular lining, also called the caudal capsule, at the tail tip. Marine.

Type species: T. tardus de Man, 1893 (8 species).

Remarks. As was pointed out by Tchesunov et al. (2014), the family Oxystominidae has two morphologically similar genera, Litinium and Thalassoalaimus . In their emended diagnosis of Litinium , one of the most important characters defining the genus is the absence of a caudal capsule. Hence, many putative species of Thalassoalaimus seem to be placed in the wrong genus because they have more characters of Litinium than of Thalassoalaimus . We present here revised species lists for both genera along with a list of species inquirendae for Thalassoalaimus .