GRIPHOBILHARZIA-AMOENA N-GEN, N-SP (DIGENEA, SCHISTOSOMATIDAE), A PARASITE OF THE FRESH-WATER CROCODILE CROCODYLUS-JOHNSTONI (REPTILIA, CROCODYLIA) FROM AUSTRALIA, WITH THE ERECTION OF A NEW SUBFAMILY, GRIPHOBILHARZIINAE

Griphobilharzia amoena n. gen., n. sp. is described from wild and farm-reared freshwater crocodiles, Crocodylus johnstoni, from the Northern Territory, Australia. The male digene is distomate, with ceca that terminate just posterior to the beginning of the gynecophoric region. There is a single oval testis located between the posterior end of the gynecophoric region and the posterior end of the body. The female is enclosed completely in a gynecophoric chamber of uncertain origin, and lies anti-parallel to the male. The female lacks an acetabulum, and it produces thin-shelled eggs. A new subfamily Griphobilharziinae (family Schistosomatidae) is proposed to contain the new species. The presence of a schistosome in a member of the Crocodylia suggests that the origin of dioecy occurred prior to the divergence of the avian lineage from the ancestral archosaurs.