Redescription of Zoniolaimus mawsonae Beveridge, 1983 (Nematoda: Strongyloidea) and the description of Z. latebrosus n. sp. from the red kangaroo Macropus rufus (Marsupialia: Macropodidae) based on morphological and molecular data.

This study shows that the description of Z. mawsonae given by Beveridge (1983) represented a composite of two species. Hence, Z. mawsonae Beveridge, 1983 is re-described and a new species, Z. latebrosus, is described. Males of the two species differ in the lengths of their spicules (0.94-1.23 mm in Z. mawsonae compared with 1.53-1.95 mm in Z. latebrosus) and in several characteristics of the bursa and genital cone. Females of the two species can be identified based on the shape of the posterior end of the body, that of Z. mawsonae being markedly swollen. Molecular data, obtained from single strand conformation polymorphism (SSCP) analysis and DNA sequencing of the second internal transcribed spacer of ribosomal DNA, provided additional support for the separation of the two species.