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SYNOPTIC DESCRIPTION OF THE PHYLUM APICOMPLEXA

SYNOPTIC DESCRIPTION OF THE PHYLUM APICOMPLEXA (LEVINE 1970)

EUKARYA> CHROMALVEOLATA> ALVEOLATAE> APICOMPLEXA
APICOMPLEXA LINKS

Introduction

Hierarchical Classification

Description of the phylum is taken from Gajadhar et al. (1991), Cavalier-Smith (1993), Schlegel (1994), Lipscomb (1991), Patterson (1999), Margulis and Schwartz (1988, Pr-19 and 1998, Pr-9), Sleigh et al. (1984), Lee et al. (1985), Grell (1976), and Vivier and Desportes (1990).

I. SYNONYMS: Sporozoans, telosporideans, apicomplexans.

II. NUMBER: >5,000 species.

III. PHYLUM CHARACTERISTICS:

  • A. Structure and Physiology
    • Cell Form: Unicellular with complex lifecycle, one stage of which has an apical complex of a conoid (text with tooltip) An conoid is part of the apical complex in the apicomplexa. It is made of a characteristic spiraled microtubular arrangement at the apex of the cell. , rhoptries (text with tooltip) An rhoptery is part of the apical complex in the apicomplexa. It is a variously shaped body that likely is involved in secretions from the cell that enable its entry into a host cell. and/or more slender micronemes (text with tooltip) Micronemes are dense bodies associated with the apical complex in the apicomplexa. They seem to be secretion bodies from the golgi. surrounded by one or two polar rings.
    • Flagella: Flagella found only in the motile gamete (sperm). One, two or three posteriorly directed whiplash (text with tooltip) (1) A whiplash flagellum is a eukaryotic 9+2 flagellum with few or no flagellar hairs or scales. These may be directed anteriorly or posteriorly. (2) A whiplash flagellum is free of hair-like mastigonemes and usually is trailing or posteriorly-directed. flagella, although reports differ as to number and orientation.
    • Basal Bodies: Orientation? Basal bodies (text with tooltip) Basal bodies (also called kinetosomes) are organelles that are not membrane-bound. All eukaryotic flagella (also called undulipodia) are underlain or attached to the cell by the basal body. The basal body is a microtubular structure with the general formula 9(3)+0. They are indistinguishable from centrioles. made of 9 singlet microtubules in coccidians and gregarines; hemosporidians and piroplasmids have normal triplets in their basal bodies.
    • Cell Covering: Pellicle (text with tooltip) A pellicle is a complex outer cellular covering that occurs within the bounds of the plasmalemma. Often synonymous with the term theca, a pellicle defines such groups as the euglenoid-kinetoplastid clade amd the Kingdom Alveolatae. of three membrane layers (the alveolar (text with tooltip) Alveoli (n.) are membrane-bound sacs that lie beneath the plasmalemma in the Kingdom Alveolata (Dinoflagellates, Ciliates, and Apicomplexans). The presence of alveoli appears to be one of the defining synapomorphies of the group. structure) with micropores.
    • Chloroplasts: Not present, though they do have colorless plastids.
    • Food Reserves: Not known.
    • Mitochondria: Tubular cristae (text with tooltip) Mitochondrial cristae that form as extended saccate structures or tubes are called tubular cristae. .
    • Golgi (text with tooltip) Golgi apparatus (also called dictyosome) is an internal membrane system of stacked flattened sacs. They occur in nearly all eukaryotes and are involved in storing and secreting cellular products. : Present.
    • Nucleus: Haploid.
    • Centrioles: Not present.
    • Inclusions and Ejectile Organelles: Not present.
  • B. Mitosis, Meiosis and Life History
    • Mitosis: Closed (text with tooltip) Mitosis is closed when the segregation of daughter chromosomes occurs within the bounds of the nuclear membrane (the nuclear membrane does not break down). with an intranuclear spindle (text with tooltip) An intranuclear spindle elaborates within the nuclear membrane of an organism with closed mitosis. ; some open at the poles. Division usually by schizogony (text with tooltip) Schizogony is the multiple cytokinesis of a plasmodial (multinucleate) cell to form a population of uninucleate cells. This is a typical type of cytokinesis in apicomplexans, microsporans, and myxozoans. Schizonony that produces merozoites (the infective form) is called merogony. .
    • Meiosis: Present; zygotic (text with tooltip) An organism is said to undergo zygotic meiosis when the zygote is the only diploid cell in the life cycle. Thus, the life history is haplontic (primarily haploid). .
    • Sexual Reproduction and Life History: Complex with oogamy and alternation of haploid and diploid generations. Summary Life History of the Apicomplexa.
  • C. Ecology: Parasites of animals.
LITERATURE CITED

Baldauf, S. L. 2003a. The deep roots of eukaryotes. Science. 300 (5626): 1701-1703.

Cavalier-Smith, T. 1993. Kingdom protozoa and its 18 Phyla. Microbiological Reviews. 57: 953-994.

Gajadhar, A. A., W. C. Marquardt, R. Hall, J. Gunderson, E. V. A. Carmona, and M. L. Sogin. 1991. Ribosomal RNA sequences of Sarcocystis muris, Theileria annulata, and Crypthecodinium cohnii reveal evolutionary relationships among apicomplexans, dinoflagellates, and ciliates. Molecular and Biochemical Parasitology. 45:147-154.

Grell, K. G. 1973. Protozoology. Springer-Verlag. New York.

Kudo, R. R. 1966. Protozoology. 5th ed. Charles C. Thomas Publisher. Springfield.

Lee, J. J., S. H. Hunter, and E. C. Bovee, eds. 1985. An Illustrated Guide to the Protozoa. Society of Protozoologists. Lawrence, Kansas.

Levine, N. D. 1985. Phylum Apicomplexa. In: Lee, J. J., S.H. Hunter, and E. C. Bovee, eds. An Illustrated Guide to the Protozoa. Allen Press. Lawrence, Kansas. pp. 322-374.

Lipscomb, D. L. 1991. The Kingdoms and the Protozoa. In Kreier, J., ed. Parasitic Protozoa. 2nd ed. Academic Press.

Margulis, L. and K. Schwartz. 1988. Five kingdoms, an illustrated guide to the phyla of life on earth. 2nd Edition. W.H. Freeman and Co. New York.

Margulis, L. and K. Schwartz. 1998. Five kingdoms, an illustrated guide to the phyla of life on earth. 3rd Edition. W. H. Freeman and Company. New York.

Patterson, D. J. 1999. The diversity of eukaryotes. American Naturalist. 154 (Suppl.): S96–S124.

Pereira, R. M., D. F. Williams, J. J. Becnel, and D. H. Oi. 2002. Yellow-head disease caused by a newly discovered Mattesia sp. in populations of the red imported fire ant, Solenopsis invicta. Journal of Invertebrate Pathology. 81: 45-48.

Perkins, F. O., J. R. Barta, R. E. Clopton, M. A. Peirce, and S. J. Upton. 2000. Phylum Apicomplexa. In: Lee, J. J., G. F. Leedale, and P. Bradbury, eds. An Illustrated Guide to the Protozoa. 2nd ed. Society of Protozoologists. Lawrence, KS. Vol 1. pp.190-369.

Sleigh, M.A., J. D. Dodge and D. J. Patterson. 1984. Kingdom Protista. In: Barnes, R. K. S., ed. A Synoptic Classification of Living Organisms. Sinauer Associates, Inc. Sunderland, Mass.

Taylor, F. J. R. 1999. Ultrastructure as a control for protistan molecular phylogeny. The American Naturalist. 154(supplement): S125-S136.

Vivier, E. and I. Desportes. 1990. Apicomplexa. In: Margulis, L., J.O. Corliss, M. Melkonian, and D.J. Chapman, eds. 1990. Handbook of the Protoctista; the structure, cultivation, habits and life histories of the eukaryotic microorganisms and their descendants exclusive of animals, plants and fungi. Jones and Bartlett Publishers. Boston. pp. 549-573.
By Jack R. Holt. Last revised: 02/20/2012
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