Oxyuridan (Nematoda) parasites of Scaphiostreptus seychellarum with comments on the families Pulchrocephalidae Kloss, 1959 and Travassosinematidae Rao, 1958

Abstract

Thelastoma retrovulvaris n.sp. and Travassosinema dechambrieri n.sp. (Oxyurida; Nematoda) are described from Scaphiostreptus seychellarum (Spirostreptida; Diplopoda) from the Seychelles. Thelastoma retrovulvaris differs from all other Thelastoma spp. except T. delphyhystera Dollfus, 1964 by the posterior position of the vulva. The latter species, not sufficiently known to permit critical comparison with the present material, is considered a species inquirenda. Travassosinema dechambrieri differs from T. travassosi Rao, 1958, type and only other species of the genus, in having coiled amphids and a shorter tail in the female and by the fact that the body narrows abruptly just posterior to the vulva. Travassosinema Rao, 1958 is characterized by the presence of a series of wing-like cuticular expansions arranged radially about the anterior extremity; such a cephalic umbraculum occurs in somewhat different form in Pulchrocephala and Indiana. Details of the cephalic umbraculum are compared in the three genera and a hypothetical transformation series is presented. A phylogenetic analysis is presented for Travassosinema, Indiana, and Pulchrocephala, and related genera Mirzaiella, Singhiella, Chitwoodiella, and Binema.