Bucephalidae

Bucephalidae
Cercaria larva of Bucephalus polymorphus from Encyclopædia Britannica, Eleventh Edition
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Platyhelminthes
Class: Trematoda
Order: Plagiorchiida
Suborder: Bucephalata
Superfamily: Bucephaloidea
Family: Bucephalidae
Poche, 1907

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 define the genera of the family.[1] It is one of the largest digenean families, with 25 genera containing hundreds of described species.[2] Bucephalids are cosmopolitan, having been recorded all over the world. They are parasites of fish from freshwater, marine, and brackish water habitat types.[2]

The name Bucephalus, meaning "ox head", was originally applied to the genus Bucephalus because of the horn-like appearance of the forked tail (furcae) of its cercaria larva. By what Manter calls a "curious circumstance", horns are also suggested by the long tentacles of adult worms.[3]

These flatworms typically occur in teleost fishes as sexually reproducing adults. In their intermediate hosts, which include mollusks and at least one amphibian, they occur as asexually reproducing stages.[4]

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.[5] 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.[6]

A schematic reconstruction of the mature spermatozoon of a bucephalid [6]
  1. ^ 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.
  2. ^ a b Muñoz, G. & Bott, N. J. (2011). A new species of Prosorhynchoides (Trematoda, Bucephalidae) from the intertidal rocky zone of central Chile. Archived 3 March 2016 at the Wayback Machine Acta Parasitologica, 56(2), 140–146.
  3. ^ 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.
  4. ^ Bott, N. J. "Bivalves and the Bucephalidae: A parasitic system on the Great Barrier Reef". PhD Thesis. University of Queensland. Retrieved 20 February 2011.
  5. ^ Gibson, D, Arlene, J. & Bray, R. (2002). Keys to the Trematoda, Volume 1. London: CAB International and The Natural History Museum.
  6. ^ a b Ibnou Ndiaye, Papa; Marchand, Bernard; Bâ, Cheikh Tidiane; Justine, Jean-Lou; Bray, Rodney A.; Quilichini, Yann (2018). "Ultrastructure of mature spermatozoa of three Bucephalidae (Prosorhynchus longisaccatus, Rhipidocotyle khalili and Bucephalus margaritae) and phylogenetic implications". Parasite. 25: 65. doi:10.1051/parasite/2018065. ISSN 1776-1042. PMC 6284405. PMID 30526820. Open access icon