Colacium

Colacium
Colacium vesiculosum , attached to a rotifer
Scientific classification
Domain:	Eukaryota
Clade:	Discoba
Phylum:	Euglenozoa
Class:	Euglenida
Clade:	Euglenophyceae
Order:	Euglenales
Family:	Euglenaceae
Genus:	Colacium Ehrenberg, 1834
Type species
Colacium vesiculosum Ehrenberg [1]

Colacium is a genus of algae belonging to the family Euglenaceae. ^[2] It has two phases: a motile phase and a sessile phase, where it is found attached to other freshwater organisms. ^[3]

The genus has a cosmopolitan distribution. ^[2]

Description

Colacium is a single-celled or colonial organisms. Cells are small, about 20–40 μm, and are similar to that of Euglena , and are metabolic with parietal, lobed chloroplasts each with a pyrenoid, and monomorphic, small paramylon grains. In its typical sessile phase, the cells are attached to a substrate via a mucilaginous stalk or short pillow. Cells divide to form colonies where the cells are attached by branched, dendroidal stalks. ^[4]

Cells of Colacium can grow a flagella and become motile, escaping from the colony as a free-swimming cell. ^[4]

Species: ^[2]

• Colacium arbuscula Stein, 1878
• Colacium mucronatum Bourr. & Chadef.
• Colacium sideropus Skuja
• Colacium simplex Hub.-Pest.
• Colacium steinii Kent
• Colacium vesiculosum Ehrenberg, 1838

References

1. Guiry, M.D.; Guiry, G.M. "Colacium Ehrenberg, 1834". AlgaeBase . University of Galway . Retrieved 28 April 2025.
2. "Colacium Ehrenberg, 1834". www.gbif.org. Retrieved 17 April 2021.
3. Rosowski, James R.; Kugrens, Paul (1973). "Observations on the euglenoid Colacium with special reference to the formation and morphology of attachment material". Journal of Phycology. 9 (4): 370–383. doi:10.1111/j.1529-8817.1973.tb04110.x. S2CID   83651870.
4. Triemer, Richard E.; Zakryś, Bożena (2014). "Chapter 10. Photosynthetic Euglenoids". In Wehr, John D.; Sheath, Robert G.; Kociolek, J. Patrick (eds.). Freshwater Algae of North America: Ecology and Classification (2 ed.). Elsevier Inc. ISBN   978-0-12-385876-4.