''Echinozoon'' 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 The alveolates (meaning "pitted like a honeycomb") are a group of protists, considered a major clade and superphylum within Eukarya. They are currently grouped with the stramenopiles and Rhizaria among the protists with tubulocristate mitochondr ...

of 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 ...

. There is one species in this genus - ''Echinozoon hoogstraali''.

History

The species and genus was described in 1951 by Garnham. The parasite was isolated from a bush rock hyrax ('' Heterohyrax brucei hoogstraali'') in 1950 by Hoogstraal and Lawless in

Torit Torit is a city of Eastern Equatoria State in South Sudan. History On 18 August 1955, the Equatoria Corps mutinied at Torit, starting the First Sudanese Civil War. In 1964 the military government in Khartoum closed "all the Christian mission ...

South Sudan South Sudan (; din, Paguot Thudän), officially the Republic of South Sudan ( din, Paankɔc Cuëny Thudän), is a landlocked country in East Africa. It is bordered by Ethiopia, Sudan, Central African Republic, Democratic Republic of the C ...

Description

Filaments are present on parasitized erythrocytes making their identification easy. The earliest stages (ring forms) are less than two micrometers in size and are oval or round in shape. No filaments are evident at this stage unlike all later stages. The parasites occur singly in the erythrocytes. A vacuole is present. The nucleus is irregular. Later stages occur in two forms. The smaller of these may be up to 5 micrometers in size, circular in outline, with pale blue cytoplasm that is free of granules. The nucleus lies to the side of the vacuole. The larger form may be up to nine micrometers in size. The cytoplasm is reddish purple in colour and may contain granules. It is oval or pear shaped. The host erythrocyte may be enlarged. The nucleus lies to one side.

Trophozoite A trophozoite (G. ''trope'', nourishment + ''zoon'', animal) is the activated, feeding stage in the life cycle of certain protozoa such as malaria-causing ''Plasmodium falciparum'' and those of the '' Giardia'' group. (The complement of the trophozo ...

s: these multiply by binary fission in the

erythrocyte Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "holl ...

s and form pairs.

Vectors

The

tick Ticks (order Ixodida) are parasitic arachnids that are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, species, and "fullness". Ticks are external parasites, living by ...

'' Haemaphysalis bequaerti'' may be the vector for this species.

References

Monotypic SAR supergroup genera Apicomplexa genera Piroplasmida Parasites of mammals {{Apicomplexa-stub