Gastrodiscoides

Gastrodiscoides
Adult G. hominis
Scientific classification
Kingdom:	Animalia
Phylum:	Platyhelminthes
Class:	Trematoda
Subclass:	Digenea
Order:	Echinostomida
Family:	Paramphistomidae
Genus:	Gastrodiscoides Leiper, 1913
Type species
Gastrodiscoides hominis (Lewis and McConnell, 1876) Leiper, 1913

Gastrodiscoides is genus of zoonotic fluke under the class Trematoda. It has only one species, Gastrodiscoides hominis. It is a parasite of a variety of vertebrates including human. In fact the first definitive specimen was described from human subject in 1876. It is prevalent in Bangladesh, India, Burma, China, Kazakhstan, Philippines, Thailand, Vietnam, and Volga Delta in Russia; with isolated cases from Africa, such as Nigeria.

Its natural habitat is the colon of pigs, and has also been found in rhesus monkey, orang-utan, fish, field rats and Napu mouse-deer. In humans the habitat is on the wall of the caecum.

The worm was discovered and described by two British medical doctors, Timothy Richard Lewis and James McConnell in 1876, from the caecum of an Assamese man in India. Their description of the internal structure was inaccurate and incomplete. They claimed that the parasite had one testis and one ovary. They placed it in the genus Amphistomum, because of its obvious location of posterior sucker; hence named Amphistomum hominis, as it was found in human. In 1902, F. Fischoeder recognised the affinity with other species and tentatively placed it in the genus Gastrodiscus (Leuckart, 1877). However, the generic name was largely recognised as synonym; hence known as Amphistomum (Gastrodiscus) hominis. With a fresh look, J.W.W. Stephens redescribed the parasite in 1906, and clearly noted the overlooked relatively small ovary and interpretation of the posterior testis as an ovary in the original description. But he nonetheless succumbed to the prevailing taxonomic position.

...
Wikipedia