SYNOPTIC DESCRIPTION OF THE PHYLUM ACTINOPHRYIDA
| EUKARYA> CHROMALVEOLATA> HETEROKONTAE> ACTINOPHRYIDA |
ACTINOPHRYIDA LINKS
| The following description comes from Patterson (1999) and Febvre-Chevalier (1990). |
I. SYNONYMS: heliozoans, sun animals, sarcodina, actinopods.
II. NUMBER: >40 species?
III. PHYLUM CHARACTERISTICS:
- A. Structure and Physiology
- Cell Form: Unicellular.
- Flagella: Not known.
- Basal Bodies: Not known.
- Cell Covering: Naked with radiating axopods (text with tooltip) An axopod is a thin pseudopodium that is permanent and stiff due to the presence of an internal microtubular structure. This is characteristic of the Actinopodotista. supported by microtubules in a double polygonal spiral and attached to the nucleus.
- Chloroplasts: Not present.
- Food Reserves: Not reported.
- 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 and associated with the nucleus.
- Nucleus: Uninucleate to multinucleate. Endosome?
- Centrioles: Not reported.
- Inclusions and Ejectile Organelles: Food vacuoles.
- B. Mitosis, Meiosis and Life History
- Mitosis: Poorly known. Open mitosis with the nuclear envelope fragmenting and spindle penetrating from the cytoplasm.
- Meiosis: Not reported.
- Sexual Reproduction and Life History: Not reported.
- C. Ecology: Freshwater and marine; free-living, filter feeders.
| LITERATURE CITED Febvre-Chevalier, C. 1990. Heliozoa. 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. 347-362. Grell, K. G. 1973. Protozoology. Springer-Verlag. New York. Kudo, R.R. 1966. Protozoology. 5th ed. Charles C. Thomas Publisher. Springfield. Mikrjukov, K.A. and D.J. Patterson. 2001. Taxonomy and phylogeny of Heliozoa. III. Actinophryids. Acta Protozoologica. 40: 3-25. Nikolaev, S. I., C. Berney, J. Fahrni, I. Bolivar, S. Polet, A. P. Mylnikov, V. V. Aleshin, N. B. Petrov, and J. Pawlowski. 2004. The twilight of Heliozoa and rise of Rhizaria, an emerging supergroup of amoeboid eukaryotes. Proceedings of the National Academy of Sciences. USA. 101(21): 8066-8071. Patterson, D. J. 1999. The diversity of eukaryotes. American Naturalist. 154 (Suppl.): S96–S124. Smith, R. M. and D. J. Patterson. 1986. Analyses of heliozoan interrelationships: an example of the potentials and limitations of ultrastructural approaches to the study of protistan phylogeny. Proceedings of the Royal Society of London. B. 227:325-266. |
| By Jack R. Holt. Last revised: 02/23/2010 |
