Featured Article Summary #48

Australiformis is a type of spiny-headed parasite found in marsupials in Australia and New Guinea. It has a proboscis with hooks that it uses to attach to the host's gut wall. This genus contains only one species, Australiformis semoni. It is similar to another genus called Moniliformis, but it lacks spiral muscles in its proboscis receptacle. The female worms are larger than the males, with lengths ranging from 95 to 197 millimeters. Infestation by A. semoni can cause inflammation and ulcers in the stomach of marsupials. Australiformis is a type of parasitic worm that belongs to the acanthocephalans group. The species, Australiformis semoni, has had a complicated taxonomic history, with various name changes over time. Unique features of this genus include a double-walled proboscis receptacle, eight cement glands, and the parasitizing of marsupials. However, genetic testing has not been done to confirm its classification. The A. semoni species has a long proboscis covered in hooks, with the females being around twice as long as the males. The proboscis has 12 rows of hooks, with the first few being large and aligned in straight rows, and the rest being small and arranged in spirals. The trunk is thin at the front and thicker at the back, and the body contains long, twisted bundles of sensory nerve fibers. The eggs have three membranes, and the males have sensory pores and oval cement glands. Both sexes have a genital pore at the end of the trunk. A. semoni is found in several provinces of Australia, including Queensland, New South Wales, and Tasmania. It has also been found in Boroko, Papua New Guinea. The Upper Burnett River region in south-eastern Queensland is the type locality. The life cycle of Australiformis involves infecting an intermediate host, which is usually an insect, and then growing and developing in its intestines. Once fully grown, the parasites are consumed by the definitive host, usually a marsupial, and attach to the walls of its intestines where they reproduce. The parasites have been found to cause ulcerative granulomatous gastritis in some hosts, and can also infect accidental hosts, such as the brown antechinus.