The Bucephaloidea are a

superfamily SUPERFAMILY is a database and search platform of structural and functional annotation for all proteins and genomes. It classifies amino acid sequences into known structural domains, especially into SCOP superfamilies. Domains are functional, str ...

trematode Trematoda is a Class (biology), class of flatworms known as trematodes, and commonly as flukes. They are obligate parasite, obligate Endoparasites, internal parasites with a complex biological life cycle, life cycle requiring at least two Host ( ...

flatworm Platyhelminthes (from the Greek language, Greek πλατύ, ''platy'', meaning "flat" and ἕλμινς (root: ἑλμινθ-), ''helminth-'', meaning "worm") is a Phylum (biology), phylum of relatively simple bilaterian, Segmentation (biology), ...

s, belonging to the large group

Digenea Digenea (Gr. ''Dis'' – double, ''Genos'' – race) is a class of trematodes in the Platyhelminthes phylum, consisting of parasitic flatworms (known as ''flukes'') with a syncytial tegument and, usually, two suckers, one ventral and one or ...

. Many species are

endoparasite Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The en ...

s of

mollusks Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The num ...

and

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

. The name ''Bucephalus'' meaning "ox head" was originally applied to the genus ''

Bucephalus Bucephalus (; ; – June 326 BC) or Bucephalas, was the horse of Alexander the Great, and one of the most famous horses of classical antiquity. According to the '' Alexander Romance'' (1.15), the name "Bucephalus" literally means "ox-h ...

'' because of the horn-like appearance of the forked tail (furcae) of its cercaria

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

. By what Manter calls a "curious circumstance", horns are also suggested by the long tentacles of adult worms. Most trematodes have several distinct developmental stages. The motile cercaria larva is released by the first intermediate host, typically a snail, and parasitizes a second intermediate host, where it encysts into a metacercaria. Finally, the adult flatworm typically inhabits the alimentary system or other body cavity of a fish. The families of Bucephaloidea are

Bucephalidae Bucephalidae is a family of trematodes that parasitize fish. They lack suckers, having instead a muscular organ called a "rhynchus" at the front end which they use to attach to their hosts. The characteristics of the rhynchus are used to help d ...

and

Nuitrematidae Nuitrematidae is a monotypic family of trematodes in the order Plagiorchiida Plagiorchiida is a large order of trematodes, synonymous to Echinostomida. They belong to the Digenea, a large subclass of flukes. This order contains relatively ...

Family Bucephalidae

Bucephalids are trematode parasites of fish. The intermediate hosts include mollusks and at least one

amphibian Amphibians are ectothermic, anamniote, anamniotic, tetrapod, four-limbed vertebrate animals that constitute the class (biology), class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all Tetrapod, tetrapods, but excl ...

. One characteristic feature is an anterior rhyncus or holdfast that is separate from the digestive system. They also differ from other digeneans in the configuration of the digestive systems and genitalia.

Family Nuitrematidae

This family was described in 1975 by Kurochkin. It has many features similar to the bucephalids, but the body is sharply subdivided in two parts. The family is monotypic; it contains only one genus, ''Nuitrema''.

References

Plagiorchiida Animal superfamilies Taxa named by Franz Poche {{trematode-stub