''Haemocystidium'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of parasitic alveolates belonging to the

phylum In biology, a phylum (; plural: phyla) is a level of classification or taxonomic rank below kingdom and above class. Traditionally, in botany the term division has been used instead of phylum, although the International Code of Nomenclature f ...

Apicomplexia The Apicomplexa (also called Apicomplexia) are a large phylum of parasitic Alveolata, alveolates. Most of them possess a unique form of organelle that comprises a type of non-photosynthetic plastid called an apicoplast, and an apical complex stru ...

History

The genus ''Haemocystidium'' was created to give a name to the haemoproteid of a gecko belonging to the genus '' Hemidactylus'' in

Sri Lanka Sri Lanka (, ; si, ශ්‍රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...

by Castellani and Willey in 1904. A second species in this genus was described in 1909 by Johnston and Cleland who found pigmented

gametocyte A gametocyte is a eukaryotic germ cell that divides by mitosis into other gametocytes or by meiosis into gametids during gametogenesis. Male gametocytes are called ''spermatocytes'', and female gametocytes are called ''oocytes''. Development ...

s in the blood of the

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

tortoise Tortoises () are reptiles of the family Testudinidae of the order Testudines (Latin: ''tortoise''). Like other turtles, tortoises have a turtle shell, shell to protect from predation and other threats. The shell in tortoises is generally hard, ...

Chelodina longicollis The eastern long-necked turtle (''Chelodina longicollis'')Kennett, R., Roe, J., Hodges, K., and Georges, A. 2009. ''Chelodina longicollis'' (Shaw 1784) – eastern long-necked turtle, common long-necked turtle, common snake-necked turtle. ''In'': ...

''. These species were transferred to ''Haemoproteus'' in 1926 by Wenyon. The genus was resurrected by Garnham in 1966 when he created a new generic name - '' Simondia'' - for the haemoproteids of

chelonia The green sea turtle (''Chelonia mydas''), also known as the green turtle, black (sea) turtle or Pacific green turtle, is a species of large sea turtle of the family Cheloniidae. It is the only species in the genus ''Chelonia''. Its range exten ...

ns. He followed the opinions of Wenyon, Hewitt and DeGiusti and suggested that all these parasites belonged to the one species - '' Simondia metchnikovi''. He retained the name ''Haemocystidium'' for the haemoproteids of

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...

s. Levine and Campbell in 1971 moved all the species in ''Simondia'' and ''Haemocystidium'' into ''

Haemoproteus ''Haemoproteus'' is a genus of alveolates that are parasitic in birds, reptiles and amphibians. Its name is derived from Greek: ''Haima'', "blood", and ''Proteus'', a sea god who had the power of assuming different shapes. The name ''Haemoproteu ...

'' an opinion that was followed by subsequent authors. The genus ''Haemocystidium'' was resurrected again by Telford in 1996 when he described three new species of protozoa in geckos from

Pakistan Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...

. The haemosporidians found in reptiles have been classified into several families; Haemoproteidae, genera Haemoproteus sp. and Haemocystidium González, L. P., Pacheco, M. A., Escalante, A. A., Jiménez Maldonado, A. D., Cepeda, A. S., Rodríguez-Fandiño, O. A., Vargas-Ramírez, M., & Matta, N. E. (2019). Haemocystidium spp., a species complex infecting ancient aquatic turtles of the family Podocnemididae: First report of these parasites in Podocnemis vogli from the Orinoquia. International journal for parasitology. Parasites and wildlife, 10, 299–309. https://doi.org/10.1016/j.ijppaw.2019.10.003 This genus like those of many protozoa may be further modified once additional DNA sequences are available.

Description

''Haemocystidium'' is distinguished from ''

Plasmodium ''Plasmodium'' is a genus of unicellular eukaryotes that are obligate parasites of vertebrates and insects. The life cycles of ''Plasmodium'' species involve development in a blood-feeding insect host which then injects parasites into a vert ...

'' by the absence of an asexual cycle in circulating blood cells It is distinguished from ''

'' by meronts that do not form as pseudocytomeres.

References

{{Taxonbar, from=Q5638240 Haemosporida Apicomplexa genera Parasites of lizards