Bucephalidae is a family of

trematode Trematoda is a class of flatworms known as flukes. They are obligate internal parasites with a complex life cycle requiring at least two hosts. The intermediate host, in which asexual reproduction occurs, is usually a snail. The definitive host ...

s that

parasitize Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has c ...

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

. 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 define the

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...

of the family.Hassanine, R. M. E. (2002)
On three digenean trematodes (Family Bucephalidae) from marine teleost fishes with new record from the Red Sea.
''Egyptian Journal of Aquatic Biology and Fisheries'', 6(3), 1–16. It is one of the largest digenean families, with 25 genera containing hundreds of described species.Muñoz, G. & Bott, N. J. (2011)
A new species of ''Prosorhynchoides'' (Trematoda, Bucephalidae) from the intertidal rocky zone of central Chile.
''Acta Parasitologica'', 56(2), 140–146. Bucephalids are

cosmopolitan Cosmopolitan may refer to: Food and drink * Cosmopolitan (cocktail), also known as a "Cosmo" History * Rootless cosmopolitan, a Soviet derogatory epithet during Joseph Stalin's anti-Semitic campaign of 1949–1953 Hotels and resorts * Cosmopoli ...

, having been recorded all over the world. They are parasites of fish from

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

, and

brackish Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...

water habitat types. The name ''Bucephalus'', meaning "ox head", was originally applied to the genus ''

Bucephalus Bucephalus or Bucephalas (; grc, Βουκεφάλας, ; – June 326 BC) was the horse of Alexander the Great, and one of the most famous horses of classical antiquity. Ancient historical accounts state that Bucephalus' breed was tha ...

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

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The ...

. By what Manter calls a "curious circumstance", horns are also suggested by the long tentacles of adult worms.Manter, H. W. (1940). Digenetic trematodes of fishes from the Galapagos Islands and the neighboring Pacific. ''Reports on the Collections Obtained by the Allan Hancock Pacific Expeditions of Valero III off the Coast of Mexico, Central America, South America, and Galapagos Islands in 1932, in 1933, in 1934, in 1935, in 1936, in 1937, and in 1938'', 2(14), 329–496. These flatworms typically occur in

teleost Teleostei (; Greek ''teleios'' "complete" + ''osteon'' "bone"), members of which are known as teleosts ), is, by far, the largest infraclass in the class Actinopterygii, the ray-finned fishes, containing 96% of all extant species of fish. Tel ...

fishes as sexually reproducing adults. In their intermediate hosts, which include

mollusks Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

and at least one

amphibian Amphibians are tetrapod, four-limbed and ectothermic vertebrates of the Class (biology), class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terres ...

, they occur as asexually reproducing stages. The 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.Gibson, D, Arlene, J. & Bray, R. (2002). ''Keys to the Trematoda, Volume 1''. London: CAB International and The Natural History Museum. The intestine is simple and saccular; they have no acetabulum. The spermatozoa of adult bucephalids has been studied by transmission electron microscopy in several species belonging to the Bucephalinae and Prosorhynchinae, but, in the absence of data on the three other subfamilies, these studies could not provide information on the phylogenetic relationships within the family. Parasite180130-Figure 6 - spermatozoa of Bucephalidae

Parasite180130-Figure 6 - spermatozoa of Bucephalidae

Genera

The genera are organised by their subfamilies. *Bucephalinae Poche, 1907 **'' Alcicornis'' MacCallum, 1917 **''

'' von Baer, 1827 **'' Glandulorhynchus'' Thatcher, 1999 **'' Parabucephalopsis'' Tang & Tang, 1976 **'' Prosorhynchoides'' Dollfus, 1929 **'' Pseudobucephalopsis'' Long & Lee, 1964 **'' Pseudorhipidocotyle'' Wang & Pan in Long & Lee, 1964 **'' Rhipidocotyle'' Diesing, 1858 **'' Rhipidocotyloides'' Long & Lee, 1964 **'' Roparhynchus'' Gupta & Kumari, 1978 *Dolichoenterinae Yamaguti, 1958 **'' Dolichoenterum'' Ozaki, 1924 **'' Grammatorcynicola'' Bott & Cribb, 2005 **'' Pseudodolichoenterum'' Yamaguti, 1971 *Heterobucephalopsinae Nolan, Curran, Miller, Cutmore, Cantacessi & Cribb, 2015 **'' Heterobucephalopsis'' Gu & Shen, 1983 *Paurorhynchinae Dickerman, 1954 **'' Bellumcorpus'' Kohn, 1962 **'' Paurorhynchus'' Dickerman, 1954 **'' Rhoporhynchus'' Wang, 1995 *Prosorhynchinae Nicoll, 1914 **'' Dollfustrema'' Eckmann, 1934 **'' Muraenicola'' Nolan & Cribb, 2010 **'' Myorhynchus'' Durio & Manter, 1968 **'' Neidhartia'' Nagaty, 1937 **'' Neoprosorhynchus'' Dayal, 1948 **'' Prosorhynchus'' Odhner, 1905 **'' Pseudoprosorhynchus'' Yamaguti, 1938 **'' Telorhynchus'' Crowcroft, 1947

References

Trematode families Plagiorchiida Trematodes parasiting fish Taxa named by Franz Poche {{trematoda-stub