Australiformis

Australiformis
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Acanthocephala
Class:	Archiacanthocephala
Order:	Moniliformida
Family:	Moniliformidae
Genus:	Australiformis Schmidt and Edmonds, 1989[1]
Species:	A. semoni
Binomial name
Australiformis semoni (Linstow, 1898)[1]
Synonyms
Echinorhynchus semoni Linstow, 1898 Gigantorhynchus semoni (Porta, 1908) Prosthenorchis semoni (Travassos, 1917) Moniliformis semoni (Johnston and Edmonds, 1952)

Australiformis is a monotypic genus of acanthocephalans (thorny-headed or spiny-headed parasitic worms) containing a single species, Australiformis semoni, that infests marsupials in Australia and New Guinea. Its body consists of a proboscis armed with hooks which it uses to pierce and hold the gut wall of its host, and a long trunk. This genus resembles species in the genus Moniliformis but is characterized by a lack of spiral muscles in the outer wall of the proboscis receptacle. The proboscis is armed with 12 rows of 13 to 15 hooks which are used to attach themselves to the small or large intestines of the host. The female worms range from 95 to 197 millimetres (3.7 to 7.8 in) long, virtually all of which is the trunk, and 1.75 to 3.5 millimetres (0.069 to 0.138 in) wide. There is pronounced sexual dimorphism in this species as females are around twice the size of the males whose trunks range from 46 to 80 millimetres (1.8 to 3.1 in) long and 2 millimetres (0.079 in) wide. Infestation by A. semoni may cause debilitating inflammation of the stomach (gastritis) with granulomatous ulcers.