The gastrointestinal nematodes of Varanus rosenbergi (Reptilia: Varanidae) and the effects of habitat change in southern Australia, with particular reference to the genus Abbreviata (Physalopteroidea)

Abstract

Nine species of nematode were collected from the stomachs of 56 Varanus rosenbergi from southern Australia, viz. Abbreviata anomala, A. antarctica, A. confusa, A. hastaspicula, A. levicauda, A. tumidocapitis, Pseudorictularia disparilis, Maxvachonia chabaudi, and Ophidascaris pyrrhus. A. antarctica occurred in 93% of lizards. Sixty-two percent of lizards were infected with this species only, and 30% had concurrent infections with from two to five species of Abbreviata. A. levicauda and A. hastaspicula were present at low prevalence in the drier and hotter parts of this host's range. Intensity of infection with Abbreviata nematodes ranged to more than 400 adults, and more than 600 Abbreviata spp. larvae. Highest intensity of infection with A. antarctica in Western Australia was east of the agricultural areas, and in or close to reserves where the ecosystem was less disturbed. The high prevalence of nematodes in this genus across a wide range of habitat and climate types suggests a prevalent arthropod intermediate host, or a wide range of species of arthropod, which are susceptible to infection.