Acanthocephala is a group of parasitic worms known as acanthocephalans, thorny-headed worms, or spiny-headed worms, characterized by the presence of an eversible proboscis, armed with spines, which it uses to pierce and hold the gut wall of its host. Acanthocephalans have complex life cycles, involving at least two hosts, which may include invertebrates, fish, amphibians, birds, and mammals. About 1420 species have been described.
Quadrigyridae is the only family within Gyracanthocephala, an order of parasitic worms of class Eoacanthocephala. This family contains two subfamilies, ten genera and about 92 species.
Profilicollis is a genus of acanthocephalan parasites of crustaceans. The status of the genus Profilicollis has been debated, and species placed in this genus were formerly included in the genus Polymorphus. However, research on the morphology of the group and their use of hosts has concluded that Profilicollis and Polymorphus should be regarded as distinct genera, and species previously described as Polymorphus altmani are now referred to as Profilicollis altmani in taxonomic and biological literature. Profilicollis parasites infect decapod crustaceans, usually shore crabs, as intermediate hosts, and use many species of shorebirds as definitive (final) hosts.
Echinorhynchus is a genus of acanthocephalan parasitic worms. They parasitize a wide variety of fishes from both marine and fresh waters. The intermediate host is usually a crustacean.
Arhythmacanthidae is a family of parasitic worms from the order Echinorhynchida.
Cavisomidae are a family of parasitic worms from the order Echinorhynchida.
Echinorhynchidae is a family of acanthocephalan parasitic worms from the order Echinorhynchida. The adult worms live in the intestines of fishes, amphibians and reptiles. The family contains the following genera, organised by subfamily.
Fessisentis is a genus of parasitic spiny-headed worms. It is the only genus in the family Fessisentidae. This genus contains six species that are distributed across the Eastern continental United States as far west as Oklahoma and Wisconsin. These worms parasitize salamanders and fish.
Leptorhynchoididae is a family of parasitic worms from the order Echinorhynchida.
Rhadinorhynchidae is a family of parasitic worms from the order Echinorhynchida.
Plagiorhynchidae is a family of parasitic Acanthocephalan worms.
Telosentis exiguus is a widespread intestinal parasitic worm. Its hosts are marine and brackish water fish of the Mediterranean basin.
Acanthocephalus anguillae is a species of parasitic worm in the phylum Acanthocephala. An intestinal parasite, it is found both in the Baltic Sea and along the coast of California, where it is often found in the fore- and mid-gut of the Brown and Rainbow trouts.
Acanthocephalus dirus is a species of parasitic worm in the Echinorhynchidae family. Instead of having its eggs expelled from the host in feces, the gravid female detaches itself from the host's digestive tract and sinks to the bottom, where her body is consumed by the species' intermediate host, Caecidotea intermedius, a species of isopod. Upon hatching, the larvae begin to alter their host's behavior. This will manifest in lighter pigmentation and an increased attraction to predators, such as A. dirus' primary hosts.
Acanthocephaloides is a genus of parasitic worms belonging to the family Arhythmacanthidae.
Oligacanthorhynchus is a genus of parasitic worms belonging to the family Oligacanthorhynchidae.
Eocollis is a genus in Acanthocephala.
Quadrigyrus is a genus in Acanthocephala.
Pallisentis is a genus in Acanthocephala.
Octospinifer is a genus in Acanthocephala belonging to the family Neoechinorhynchidae.
