New records and species of Enchelidiidae (Nematoda): Symplocostoma brasiliensis sp. nov. and a first description of the female of Calyptronema pigmentatum Gerlach, 1957

Abstract

This contribution presents a new species of Symplocostoma, the first member of this genus identified for the coast of Brazil, and a dichotomous key for species of the genus. There is also a redescription of the male and the first description of the female of Calyptronema pigmentatum. Samples were collected on the continental shelf of the Potiguar Basin, northeastern Brazil. Symplocostoma brasiliensis sp. nov. has several distinguishing characteristics: the position of the secretory–excretory pore, tail length, the presence of denticles in the buccal cavity (female) and the number of precloacal supplements (male). The male of C. pigmentatum showed most morphological and morphometric characters of the original description, except for the size of the amphidial fovea and the number of precloacal supplements. The male differs from C. maxweberi in the spicular apparatus, gubernaculum shape, number of precloacal papillae and tail length. The female of the species has a buccal cavity similar to that of C. mawsoni, but differs in the position of the secretory–excretory pore and the shape of the amphidial fovea and tail.