DESCRIPTION OF THE PHYLUM EOPHARYNGIA (CAVALIER-SMITH 1993)
| EUKARYA> EXCAVATA> EUEXCAVATA> EOPHARYNGIA |
EOPHARYNGIA LINKS
| The following descriptions come from Vickerman (1990a), Brugerolle and Mignot (1990), Dyer (1990c), Lee et al. (1985), Grell (1973), Kudo (1966), Patterson (1999), Taylor (1999), and Cavalier-Smith (2003a). |
I. SYNONYMS: diplomonads, retortomonads.
II. NUMBER: likely no more than 100 species.
III. PHYLUM CHARACTERISTICS:
- A. Structure and Physiology
- Cell Form: Unicellular.
- Flagella: Occur in groups of four or six; usually one of which is recurrent (text with tooltip) Recurrent flagella bend to the posterior end of the cell. Typically, they are identified as recurrent when anteriorly-directed flagella are present. . Flagella inserted anterior to excavate (text with tooltip) An excavate is a feeding groove that terminates in a cytostome on the surface of certain taxa within the Excavata. Usually, they are associated with a recurrent or posteriorly-directed flagellum. feeding groove, when present. Recurrent flagella without vanes.
- Basal Bodies: Basal bodies cruciate (text with tooltip) In the form of a cross. ; rootlets from the basal bodies form bundles passing into the cytoplasm, and microtubular and/or striated roots (text with tooltip) Striated roots (also called kinetodesma, banded roots, kinetodesmal fibers, or striated fibers) are banded flagellar roots that elaborate from basal bodies. They form a distinctive and diagnostic network in the Ciliata. connect the basal bodies to the nucleus thus forming a karyomastigont unit (text with tooltip) A karyomastigont is a 'unit' that includes basal bodies, flagellar roots, and a nucleus. .
- Cell Covering: Naked but pellicular (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. microtubules may be present and support edges of the feeding groove. The groove in some is pronounced and forms a deep crypt or pocket. In many taxa, the karyomastigonts and grooves are doubled (thus the name diplomonad).
- Chloroplasts: Not present.
- Food Reserves: ?
- Mitochondria: Not present.
- 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 in retortomonads only, but no particular association with the nucleus or the flagellar roots.
- Nucleus: Connected to basal bodies via basal body roots to form a karyomastigont unit; four or six flagellar basal bodies associated with a nucleus.
- Centrioles: Not reported.
- Inclusions and Ejectile Organelles:Food vacuoles.
- B. Mitosis, Meiosis and Life History
- MITOSIS: Intranuclear spindle (text with tooltip) An intranuclear spindle elaborates within the nuclear membrane of an organism with closed mitosis. .
- MEIOSIS: Presumed.
- SEXUAL REPRODUCTION AND LIFE HISTORY: ?
- C. Ecology: Mostly commensals and parasites of animal digestive tracts. Some free-living.
| LITERATURE CITED Baldauf, S. L. 2003a. The deep roots of eukaryotes. Science. 300 (5626): 1701-1703. Brugerolle, G., and J. P. Mignot. 1990. Retortamonadida. 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. 259-265. Cavalier-Smith, T. 2003a. Protist phylogeny and the high-level classification of Protozoa. European Journal of Protistology. 39:338-348. Dyer, B. D. 1990c. Parabasalia. 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. 252-258. [L] Grell, K. G. 1973. Protozoology. Springer-Verlag. New York. Kudo, R.R. 1966. Protozoology. 5th ed. Charles C. Thomas Publisher. Springfield. Lee, J. J. 1985. Order Retortamonadida. In: Lee, J.J., S.H. Hunter, and E.C. Bovee, eds. An Illustrated Guide to the Protozoa. Allen Press. Lawrence, Kansas. pp. 118-119. Patterson, D. J. 1999. The diversity of eukaryotes. American Naturalist. 154 (Suppl.): S96–S124. Taylor, F. J. R. 1999. Ultrastructure as a control for protistan molecular phylogeny. The American Naturalist. 154(supplement): S125-S136. Vickerman, K. 1990a. Diplomonadida. 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. 200-210. |
| By Jack R. Holt. Last revised: 02/12/2012 |
