Apicomplexa

Apicomplexa
Scientific classification
Kingdom: Protista Phylum: Apicomplexa
Classes / Subclasses
Class Perkinsasida Class Colpodellasida Class Conoidasida Gregarinasina Coccidiasina Class Aconoidasida Haemosporasina Piroplasmasina

The Apicomplexa are a large group of almost exclusively parasitic protozoa, characterized by a complicated apical complex at the anterior of the cell. This complex often includes an organelle called the apicoplast, believed to be a degenerate chloroplast. They have a pellicle composed of packed alveoli, and this and other traits indicate membership in a group called the alveolates, among which they appear particularly closely related to the dinoflagellates.

Two genera of free-living flagellates, Perkinsus and Colpodella, are generally included here, though they may be closer to the dinoflagellates than to the other Apicomplexa. Aside from these, all Apicomplexa are parasites, without flagella or other locomotory structures. Some important members and their associated diseases include:

• Plasmodium sp. - Malaria
• Pneumocystis carinii - P. carinii Pneumonia
• Toxoplasma gondii - Toxoplasmosis

The Apicomplexa include the bulk of what used to be called the Sporozoa, a group for parasitic protozoans without flagella, pseudopods, or cilia.