Digenea is a class of trematodes in the Platyhelminthes phylum, consisting of parasitic flatworms with a syncytial tegument and, usually, two suckers, one ventral and one oral. Adults commonly live within the digestive tract, but occur throughout the organ systems of all classes of vertebrates. Once thought to be related to the Monogenea, it is now recognised that they are closest to the Aspidogastrea and that the Monogenea are more closely allied with the Cestoda. Around 6,000 species have been described to date.
Strongyles, or alternatively, strongyls, are nematode worms of the family Strongylidae, order Strongylida. They are often parasitic in the gastrointestinal tract of mammals, especially grazers such as sheep, cattle and horses.
The Polyceridae are a taxonomic family of sea slugs, dorid nudibranchs, marine gastropod mollusks within the superfamily Polyceroidea.
Chromodorididae, or chromodorids, are a taxonomic family of colourful, sea slugs; dorid nudibranchs, marine gastropod mollusks in the superfamily Doridoidea. “Chromodorid nudibranchs are among the most gorgeously coloured of all animals.” The over 360 described species are primarily found in tropical and subtropical waters, as members of coral reef communities, specifically associated with their sponge prey. The chromodorids are the most speciose family of opisthobranchs. They range in size from <10mm to over 30 cm, although most species are approximately 15–30 mm in size.
Plagiorchiida is a large order of trematodes, synonymous to Echinostomida. They belong to the Digenea, a large subclass of flukes. This order contains relatively few significant parasites of humans.
Zoogonidae are a family of trematodes in the order Plagiorchiida.
Echinostomata is a suborder of the parasitic flatworm order Plagiorchiida. The suborder contains numerous species that are parasitic in humans.
Psilostomatidae is a family of trematodes in the order Plagiorchiida. They parasitise aquatic vertebrates as definitive hosts.
Cadlina is a genus of sea slugs, dorid nudibranchs, shell-less marine gastropod mollusks historically classified in the family Chromodorididae. Recent research by R.F. Johnson in 2011 has shown that Cadlina does not belong to the family Chromodorididae. She has therefore brought back the name Cadlinidae from synonymy with Chromodorididae. The family Cadlinidae also includes the genus AldisaBergh, 1878.
Heterophyidae is a family of intestinal trematodes in the order Plagiorchiida.
Echinostomatidae is a family of trematodes in the order Plagiorchiida, first described in 1899.
Lepocreadiidae is a family of trematodes in the order Plagiorchiida.
Xiphidiata is a suborder of Plagiorchiida, an order of parasitic flatworms (flukes).
Azygia is a genus of flatworms belonging to the family Azygiidae.
Azygiida is an order of flatworms belonging to the class Rhabditophora.
Dicrocoeliidae is a family of flatworms belonging to the order Plagiorchiida.
Brachycladiidae is a family of trematodes belonging to the order Plagiorchiida.
Derogenidae is a family of trematodes belonging to the order Plagiorchiida.
Hemiuridae is a family of trematodes belonging to the order Plagiorchiida containing 514 described species.
Accacoelium is a genus of flatworms belonging to the family Accacoeliidae.
