SYNOPTIC DESCRIPTION OF THE PHYLUM CENTROHELOMONADA (KÜHN 1926)
| EUKARYA> CHROMALVEOLATA> HACROBIAE> CENTROHELOMONADA |
CENTROHELOMONADA LINKS
| The following description comes from Patterson (1999) and Febvre-Chevalier (1990). |
I. SYNONYMS: heliozoans, sun animals, sarcodina, actinopods.
II. NUMBER: >85 species?
III. PHYLUM CHARACTERISTICS:
- A. Structure and Physiology
- Cell Form: Unicellular.
- Flagella: Naked flagella in the dimorphids.
- Basal Bodies: Orthogonal or perpendicular (text with tooltip) Basal bodies are perpendicular (or orthogonal) when their orientation relative to each other is at a right angle. when present.
- 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 or surrounded by the nucleus. Many are covered with silicaceous scales and spicules.
- Chloroplasts: Not present.
- Food Reserves: Not reported.
- Mitochondria: Flattened cristae (text with tooltip) Flat cristae (crista, sing.) are wall-like cristae within certain mitochondria. .
- 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: Uninucleate to multinucleate. Endosome?
- Centrioles: Not reported.
- Inclusions and Ejectile Organelles: Food vacuoles.
- B. Mitosis, Meiosis and Life History
- Mitosis: Poorly known. 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). ?
- Meiosis: Not reported.
- Sexual Reproduction and Life History: Not reported.
- C. Ecology: Freshwater and marine; free-living, filter feeders.
| LITERATURE CITED Cavalier-Smith, T. 2003a. Protist phylogeny and the high-level classification of Protozoa. European Journal of Protistology. 39:338-348. Cavalier-Smith, T. and E. E. Chao. 2003c. Molecular phylogeny of centrohelid heliozoan, a novel lineage of bikont eukaryotes that arose by ciliary loss. Journal of Molecular Evolution. 56:387-396. Cavalier-Smith, T. and S. von der Heyden. 2007. Molecular phylogeny, scale evolution and taxonomy of centrohelid heliozoa. Molecular Phylogenetics and Evolution. 44: 1186-1203. 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. Leonov, M. M. 2009. Heliozoan fauna of waterbodies and watercourses of the Central Russian upland forest-steppe. Inland Water Biology. 2(1): 6-12. 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. 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. Wujek, D. E. 2003. Freshwater Heliozoa (Protista, Heliozoa) from Indiana. Proceedings of the Indiana Academy of Science. 112(2): 169-174. |
| By Jack R. Holt. Last revised: 03/04/2013 |
