Myxobolidae is a

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

myxosporea Myxosporea is a class of microscopic parasites, belonging to the Myxozoa clade within Cnidaria. They have a complex life cycle which comprises vegetative forms in two hosts, an aquatic invertebrate (generally an annelid but sometimes a bryozoan) ...

parasite 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 ...

s which typically infect freshwater

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 ...

es, and includes the economically significant

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

, '' Myxobolus cerebralis''. They have been shown to have a complex life cycle, involving an alternate stage in an invertebrate, typically an

annelid The annelids (Annelida , from Latin ', "little ring"), also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecol ...

or polychaete worm.

Morphology

Myxosporean spores of genera belonging to the Myxobolidae are flattened parallel to the sutural line. They typically contain two

polar capsule Polar capsules are structures found in the valves of Myxosporean parasites, which contain the polar filament. The polar capsule is constructed of a proteinaceous and a polysaccharide layer, both layers of which continue into the polar filament. ...

s, and have a central vacuole in which they store β-glycogen. In some genera, the spore walls are drawn out into long processes which are thought to slow sinking through the water column. Actinosporean stages which have been linked to members of the Myxobolidae have a single central "style" and three processes or "tails", around 200 micrometers long, projecting from this. A sporoplasm packet at the end of the style contains 64

germ cell Germ or germs may refer to: Science * Germ (microorganism), an informal word for a pathogen * Germ cell, cell that gives rise to the gametes of an organism that reproduces sexually * Germ layer, a primary layer of cells that forms during embry ...

s surrounded by a cellular envelope. There are also three polar capsules, each of which contains a coiled

polar filament A polar filament is a structure found in the polar capsule of myxosporean organisms. It is analogous to the "penetrant" structure found in cnidocyte A cnidocyte (also known as a cnidoblast or nematocyte) is an explosive cell containing one lar ...

Genera

*''

Dicauda ''Dicauda'' is a genus of cnidarians belonging to the family Myxobolidae Myxobolidae is a Family (biology), family of myxosporean parasites which typically infect freshwater fishes, and includes the economically significant species, ''Myxobolus ...

'' Hoffman & Walker, 1978Hoffman, G. & Walker, R. (1978). A new myxosporidan, ''Dicauda atherinodi'' n. g., n. sp. of the minnow, ''Notropis atherinoides'' Rafinesque. ''Journal of Fish Diseases'', 1(4), 343–349. *'' Hennegoides'' Lom, Tonguthai & Dyková, 1991Lom, J., Tonguthai, K. & Dyková, I. (1991). ''Hennegoides longitudinalis'' n. gen. n. sp., a myxosporean parasite of ''Osphronemus gourami'' from Thailand. ''Diseases of Aquatic Organisms'', 11, 143–145. *''

Henneguya ''Henneguya'' is a genus of myxosporean parasites belonging to the family Myxobolidae. The species of this genus are found in Europe and America. Species according to GBIF (except ''H. adherens''): * '' Henneguya adherens'' Azevedo & MatosCarlo ...

'' Thélohan, 1892 *''

Laterocaudata ''Laterocaudata'' is a genus of cnidarians belonging to the family Myxobolidae Myxobolidae is a Family (biology), family of myxosporean parasites which typically infect freshwater fishes, and includes the economically significant species, ''Myx ...

'' Chen & Hsieh, 1984 *''

Myxobolus ''Myxobolus'' is a genus of myxozoa that includes important parasites of fish like ''Myxobolus cerebralis''. The genus is polyphyletic, with members scattered throughout the myxozoa. Some stages of ''Myxobolus'' species were previously thought t ...

'' Bütschli, 1882Bütschli, O. (1882). Myxosporidia. In Bütschli, O. (Ed.), '' Dr. H. G. Bronn's Klassen und Ordnungen des Thier-Reichs, wissenschaftlich dargestellt in Wort und Bild. Erster Band. Protozoa''. Leipzig: C. F. Winter'sche Verlagshandlung. *''

Thelohanellus ''Thelohanellus'' is a genus of myxozoan in the family Myxobolidae Myxobolidae is a Family (biology), family of myxosporean parasites which typically infect freshwater fishes, and includes the economically significant species, ''Myxobolus cere ...

'' Kudo, 1933Kudo, R. R. (1933). A taxonomic consideration of Myxosporidia. ''Transactions of the American Microscopical Society'', 52, 195–216. *''

Trigonosporus ''Trigonosporus'' is a genus of cnidarians belonging to the family Myxobolidae Myxobolidae is a Family (biology), family of myxosporean parasites which typically infect freshwater fishes, and includes the economically significant species, ''Myx ...

'' Hoshina, 1952Hoshina, T. (1952). Notes on some myxosporidian parasites on fishes of Japan. ''Journal of the Tokyo University of Fisheries'', 39(1), 69–89. *''

Unicauda ''Unicauda'' is a genus of cnidarians belonging to the family Myxobolidae Myxobolidae is a Family (biology), family of myxosporean parasites which typically infect freshwater fishes, and includes the economically significant species, ''Myxobolu ...

'' Davis, 1944Davis, H. S. (1944). A revision of the genus ''Henneguya'' (Myxosporidia) with descriptions of two new species. ''Transactions of the American Microscopical Society'', 63(4), 311–320.

References

Bivalvulida Cnidarian families {{Myxozoa-stub