Parasites found in faeces of Indian elephants (Elephas maximus) in Thailand following treatment with mebendazole, with observations on Ptenderius papillatus (Cobbold, 1882) Stiles and Goldberger, 1910 by scanning electron microscopy

Three Indian elephants (Elephas maximus) in Thailand were treated with mebe ndazole at a dose of 6-7 mg/kg body weight. Four days following treatment, fecal examinations were negative for nematode eggs in all elephants and neg ative for fluke eggs in two of the animals. However, adult parasites were r ecovered from faeces from each of the animals 36-72 hours after deworming. These included Murshidia lalcilera (Cobbold, 1882) Lane 1915, M. neveule-ma irei(Witenberg, 1925) Yorke and Maplestone, 1926, a Quilonia species, and t he amphistome Plenderius papaillatus (Cobbold, 1882) Stiles and Goldberger, 1910. The finding of P. papillatus constitutes a first record oi this spec ies in Thailand. Specimens of P. papillatus were examined by scanning elect ron microscopy. In contrast to earlier descriptions of this species, no pro minent papillae were found at the anterior end. Structures on the acetabulu m that had previously been described as papillae were actually elevated por es that were spread over the acetabulum. These pores differ from all previo us descriptions of P. papillatus and indicate a highly modified acetabulum in P. papillatus relative to other Ptenderius species.