Apicomplexa

Apicomplexa
Scientific classification
Domain:	Eukaryota
Kingdom:	Chromalveolata
Superphylum:	Alveolata
Phylum:	Apicomplexa
Classes & Subclasses
Aconoidasida Haemosporasina Piroplasmasina Conoidasida Coccidiasina Gregarinasina

The Apicomplexa are a large group of protists (protozoa) which are parasitic. They have developed some extraordinary adaptations which fit them in their parasitic life. They are all single-celled, they are all parasites of animals,^[1] and they all form spores.

They have a unique organelle, a plastid called an apicoplast,^[2] and an apical complex structure which gets them into a host's cell. They do not have structures such as flagella or pseudopods except in certain gamete stages. Body movement is by flexing or gliding.

The group were once called the Sporozoa, but this name is now discouraged.^[2]

Apicomplexans have complex life cycles, and there is much variation among different apicomplexan groups. Both asexual and sexual reproduction occur. Cell nuclei are haploid.

This is a diverse group including organisms such as coccidia, gregarines, piroplasms, haemogregarines, and malarias. Diseases caused by apicomplexan organisms include:

• Babesiosis (Babesia)
• Malaria (Plasmodium)
• Coccidian diseases including:
  • Cryptosporidiosis (Cryptosporidium parvum)
  • Cyclosporiasis (Cyclospora cayetanensis)
  • Isosporiasis (Isospora belli)
  • Toxoplasmosis (Toxoplasma gondii)

1. ↑ Jadwiga Grabda (1991). Marine fish parasitology: an outline. VCH. p. 8. ISBN 0895738236.
2. ↑ ^{2.0 2.1} Introduction to the Apicomplexa