Progress in Taxonomy of the Apicomplexan Protozoa

Abstract

In 1987, 4516 species and 339 genera of the phylum Apicomplexa had been named. They consisted of the gregarines (subclass Gregarinasida) (1624 named species and 231 named genera), the hemogregarines (family Haemogregarinidae) (399 species and 4 genera), the eimeriorins (order Eimeriorida) (1771 species and 43 genera), the hemospororids (order Haemospororida) (444 species and 9 genera), the piroplasmids (order Piroplasmorida) (173 species and 20 genera), and a few others (105 species and 32 genera). The first apicomplexan protozoon was seen by Antony van Leeuwenhoek; in 1674 he saw oocysts of Eimeria stiedai in the gall bladder of a rabbit. The first member of the phylum to be named (by Dufour in 1828) was Gregarina ovata in earwigs. During the quarter century 1826-1850, 41 species and 6 genera of Apicomplexa were named. These numbers increased progressively. In the quarter century 1951-1975, 1873 new species and 83 new genera were named. Data are given for the numbers of named species and genera of apicomplexan protozoa of each group known in 1850, 1875, 1900, 1925, 1950, 1975, and 1987.

The Biological Survey of Canada: A Personal History

“…Over 100 species of Babesia have been identified in wild and domestic animals (Levine 1988). The complex life cycle of the agent involves asexual reproduction in the erythrocytes of mammalian hosts and sexual reproduction in arthropod vectors.…”

Mining thePlasmodiumgenome database to define organellar function: what does the apicoplast do?

“…Axenic culture conditions have not been established for any apicomplexan parasite save the highly divergent molluscan parasite Perkinsus marinus (Gauthier et al 1995 if not all, apicomplexans exhibit a sexual cycle, no known culture conditions permit sexual recombination for any apicomplexan parasite at any experimentally useful efficiency. Sexual crosses therefore require mosquitoes, cats, chickens, or other inconvenient laboratory animals (Levine 1988).…”

“…respects (Frenkel 1973;Levine 1988). Consider, for example, the diseases they cause: malaria is characterized by periodic fevers, toxoplasmosis by focal lesions in the central nervous system, and coccidiosis by diarrhoea and intestinal malabsorption.…”

Extrachromosomal DNA in the Apicomplexa

“…Other members of the group are numerous and widely distributed, often on marine organisms (68). All members of the phylum are obligate intracellular parasites, and they are named after a set of specialized organelles, the apical complex, which they use in attaching to or penetrating host cells.…”