SYNOPTIC DESCRIPTION OF THE PHYLUM HAPTOMONADA
| EUKARYA> CHROMALVEOLATA> HACROBIAE> HAPTOMONADA |
HAPTOMONADA LINKS
| The descriptions of the phylum come from Grell (1973), Kudo (1966) and Lee et al. (1985), Green et al. (1990), Margulis and Schwartz (1988, 1998), Sleigh et al (1985), Bold and Wynne (1985), Sze (1986), and Lee (1980). |
I. SYNONYMS: Coccolithophorids, haptomonads, haptophyta, prymnesiophytes.
II. NUMBER: >450 species.
III. PHYLUM CHARACTERISTICS:
- A. Structure and Physiology
- Cell Form: Flagellated unicells or coccoid.
- Flagella: Two flagella, both 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. and anteriorly directed (text with tooltip) (2) A whiplash flagellum is free of hair-like mastigonemes and usually is trailing or posteriorly-directed. or 2 unequal heterodynamic flagella (text with tooltip) Heterodynamic flagella occur on the same cell but beat with different patterns (e.g. anterior-posterior). ; the haptonema (text with tooltip) A haptonema is a flagellum-like structure that characterizes the Haptotista. The formula for the axonemal microtubular array is 6(1)+0. Usually functions as a holdfast. , a flagellum-like structure with a core of 6-7 single microtubules, is often present and coiled between the flagella.
- Basal Bodies: Basal bodies perpendicular (text with tooltip) Basal bodies are perpendicular (or orthogonal) when their orientation relative to each other is at a right angle. .
- Cell Covering: Covered by organic or calcareous scales (text with tooltip) Protist scales are regular overlapping structures on the outside of the cell. They may be organic, silicaceous, or carbonaceous and may serve as an articulated cell wall. Scales may occur on the cells of a range of unrelated taxa. .
- Chloroplasts: Usually 2 yellow chromoplasts (text with tooltip) Chromoplast is the general term for a photosynthetic organelle. Technically, a chloroplast is a particular chromoplast in which the dominant chlorophylls are A and B. with chlorophylls a and c1 and c2 (text with tooltip) Chlorophyll C is a variant of Chlorophyll A. and a secondary photosynthetic pigment in the many of the photosynthetic heterokonts and dinoflagellates. ; also with B-carotene, fucoxanthin (text with tooltip) Fucoxanthin is a carotenoid secondary photosynthetic pigment that occurs in many of the photosynthetic eukaryotes like the heterokonts and haptotists. and other xanthophylls (text with tooltip) Xanthophyll is an oxygenated carotenoid secondary photosynthetic pigment that occurs in many of the photosynthetic eukaryotes. ; 3 thylakoids; pyrenoid; eyespot (present in Pavlovologia) situated within the chloroplast.
- Food Reserves: Chrysolaminarin (text with tooltip) Chrysolaminarin (also called leucosin) is a storage carbohydrate that is a polymer of glucopyranoside units. Typically it is found in photosynthetic heterokonts. or paramylon (text with tooltip) Paramylon is a storage carbohydrate that is a polymer of glucose. It is in a class of compounds called glucans. It is found in euglenoids and haptophytes. ; some with lipid globules; some phagotrophic.
- 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; polarized from edge to edge and heterogeneous from face to face; often fan-shaped beneath the basal bodies.
- Nucleus: Outer membrane confluent with outer membrane of one of the chloroplasts.
- Centrioles: 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. function as centrioles.
- Inclusions and Ejectile Organelles:
- Not present in most, but some have muciferous bodies.
- B. Mitosis, Meiosis and Life History
- Mitosis: Nuclear membrane breaks down (open); spindle poles associated with basal bodies (as centrioles).
- Meiosis: Present.
- Sexual Reproduction and Life History:
- Haploid and diploid phases alternate in some species; the haploid form produces flagellated isogametes (text with tooltip) Isogametes are gametes that are equal in size. .
- C. Ecology: Mainly marine organisms.
| LITERATURE CITED Baldauf, S. L. 2003a. The deep roots of eukaryotes. Science. 300 (5626): 1701-1703. Billard, C. and I Inouye. 2004. What is new in coccolithophore biology? In: Thierstein, H. R. and J. R. Yound, eds. Molecular Processes to Global Impact. Springer Verlag, Berlin. pp. 1-29. Bold, H. C. and M. J. Wynne. 1985. Introduction to the Algae. 2nd Edition. Prentice-Hall, Inc. Englewood Cliffs. NJ. [Bold and Wynne (1985). Burki, F., K. Shalchian-Tabrizi, M. Minge, A. Skaeveland, S. I. Nikolaev, K. S. Jakobsen, and J. Pawlowski. 2007. Phylogenomics reshuffles the eukaryotic supergroups. PLoS ONE. 8:790-795. Burki, F., Y. Inagaki, J. Brate, J. M. Archibald, P. J. Keeling, T. Cavalier-Smith, M. Sakaguchi, T. Hashimoto, A. Horak, S. Kumar, D. Klaveness, K. S. Jakobsen, J. Pawlonski, and K. Shalchian-Tabrizi. 2009. Large-scale phylogenomic analyses reveal thet two enigmatic protist lineages, Telonemia and Centroheliozoa, are related to photosynthetic chromalveolates. Genome. Biol. Evol. 1(1): 231-238. Dodge, J. D. 1973. The fine structure of algal cells. Academic Press. New York. Frada, M., I. Probert, M. J. Allen, W. H. Wilson, and C. de Vargas. 2008. The “Cheshire Cat” escape strategy of the coccolithophore Emiliania huxleyi in response to viral infection. Proc. Natl. Acad. Sci. USA. 105(41): 15944-15949. Green, J. C., P. A. Course, and G. A. Tarran. The life-cycle of Emiliania huxleyi: A brief review and a study of relative ploidy levels analysed by flow cytometry. Journal of Marine Systems. 9: 33-44. Green, J. C., K. Perch-Nielsen, and P. Westbroek. 1990. Prymnesiophyta. 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. 293-317. Grell, K. G. 1973. Protozoology. Springer-Verlag. New York. Hackett, J. D., H. S. Yoon, S. Li, A. Reyes-Prieto, S. E. Rummele, and D. Bhattacharya. 2007. Phylogenomic analysis supports the monoplyly of Cryptophytes and Haptophytes and the association of Rhizaria with Chromalveolates. Molecular Biology and Evolution. 24(8): 1702-1713. Hibberd, D. J. 1980. Prymnesiophytes (=haptophytes). In: Cox, E.R., ed. Phytoflagellates. Elsevier/ North-Holland. New York. Pp. 313-317. Hibberd (1980). Kudo, R.R. 1966. Protozoology. 5th ed. Charles C. Thomas Publisher. Springfield. Laguna, R., J. Romo, B. A. Read, and T. M. Wahlund. 2001. Induction of phase variation in the lifecycle of the marine coccolithophorid Emiliania huxleyi. Applied and Environmental Microbioloogy. 67(9): 3824-3831. Lee, R. E. 1980. Phycology. Cambridge University Press. Cambridge. Lee, J. J., S. H. Hunter, and E. C. Bovee, eds. 1985. An Illustrated Guide to the Protozoa. Society of Protozoologists. Lawrence, Kansas. Lovelock, J. 1991. Scientists on Gaia. MIT Press. Cambridge, Mass. 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. Morin, P. J. 2008. Sex as an algal antiviral strategy. Proc. Natl. Acad. Sci. USA. 105(41): 15639-15640. Okamoto, N., C. Chantangsi, A. Horak, B. S. Leander, and P. J. Keeling. 2009. Molecular phylogeny and description of the novel katablepharid Roombia truncata gen. et sp. nov., and establishment of the Hacrobia taxon nov. PLoS One 4(9):e7080. Patterson, D. J. 1999. The diversity of eukaryotes. American Naturalist. 154 (Suppl.): S96–S124. 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. Sze, P. 1986. A Biology of the Algae. Wm. C. Brown Publishers. Dubuque, Iowa. Taylor, F. J. R. 1976. Flagellate Phylogeny: A Study in Conflicts. J. Protozoology. 23: 28-40. |
| By Jack R. Holt. Last revised: 03/04/2013 |
