Myxobolidae is a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

myxosporea Myxosporea is a class of microscopic animals, all of whom are parasites. They belong to the Myxozoa clade within Cnidaria. They have a complex life cycle that comprises vegetative forms in two hosts—one an aquatic invertebrate (generally an ann ...

parasite Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...

s which typically infect freshwater

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 ...

es, and includes the economically significant

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

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

annelid The annelids (), also known as the segmented worms, are animals that comprise the phylum Annelida (; ). The phylum contains over 22,000 extant species, including ragworms, earthworms, and leeches. The species exist in and have adapted to vario ...

polychaete Polychaeta () is a paraphyletic class of generally marine Annelid, annelid worms, common name, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called c ...

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. T ...

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 A germ cell is any cell that gives rise to the gametes of an organism that reproduces sexually. In many animals, the germ cells originate in the primitive streak and migrate via the gut of an embryo to the developing gonads. There, they unde ...

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

polar filament The term polar filament may refer to either of two analogous structures used for host invasion by different groups of parasites: Myxozoa (Metazoa) and Microsporidia (Fungi), respectively. In Myxozoa The polar filament is a structure found in the p ...

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, ''Myxobolu ...

'' Hoffman & Walker, 1978 *''

Hennegoides ''Hennegoides'' is a genus of cnidarian that is part of the family Myxobolidae Myxobolidae is a Family (biology), family of myxosporean parasites which typically infect freshwater fishes, and includes the economically significant species, ''My ...

'' Lom, Tonguthai & Dyková, 1991 *''

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 & Matos * '' ...

'' 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, ''My ...

'' 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 ...

'' Bütschli, 1882 *''

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, 1933 *''

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, ''My ...

'' Hoshina, 1952 *''

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, ''Myxobol ...

'' Davis, 1944

References

Bivalvulida Cnidarian families {{Myxozoa-stub