''Alveocystis'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

in the

phylum In biology, a phylum (; : phyla) is a level of classification, or taxonomic rank, that is below Kingdom (biology), kingdom and above Class (biology), class. Traditionally, in botany the term division (taxonomy), division has been used instead ...

Apicomplexa The Apicomplexa (also called Apicomplexia; single: apicomplexan) are organisms of a large phylum of mainly parasitic alveolates. Most possess a unique form of organelle structure that comprises a type of non-photosynthetic plastid called an ap ...

. Species in this genus infect worms of the family

Priapuloidea Priapulida (priapulid worms, from Gr. πριάπος, ''priāpos'' 'Priapus' + Lat. ''-ul-'', diminutive), sometimes referred to as penis worms, is a phylum of unsegmented marine worms. The name of the phylum relates to the Greek god of fertility ...

and

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

s. This genus has been poorly studied and little is known about it.

History

This genus was created by Bel'tenev in 1980.Bel'tenov, AE (1980) ''Alveocystis intestinalis'' n. sp., n. gen. - a new species of coccidian from the intestine of ''Priapulida''. Voprosy Parasitl Voddnyk Bespozvon. Zhivotnykh (Temat. Sbornik), Vilnyus, USSR 1980:10-11 The recognised first species of this genus was ''Alveocystis macrocoronata'' by Lüling in 1942.Luling KH (1943) Uber eine neue Coccidie im Darm der Pripuliden: ''Priapulus caudatus'' (Lam.) und ''Halicryptus spinulosus'' (v. Sieb.). Archiv für Protistenkunde 96:39-74

Taxonomy

Four species are recognised in this genus. Morphologically they resemble members of the genus '' Pfeifferinella''.

Description

The

oocyst Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism ...

s have no sporocysts. A distinct convex micropyle is usually present at one end of the oocyst. Within each oocyst there are 8 or more free

sporozoite Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organis ...

s and a large oocyst residuum.

References

Apicomplexa genera {{Apicomplexa-stub