''Colacium'' is a genus of

algae Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...

belonging to the family

Euglenaceae Euglenaceae (also known as Euglenidae) is a family of flagellates in the phylum Euglenozoa. The family includes the most well-known euglenoid genus, ''Euglena''. Nomenclature The family Euglenaceae is also known by the name Euglenidae. The orig ...

. It has two phases: a motile phase and a sessile phase, where it is found attached to other freshwater organisms. The genus has a

cosmopolitan distribution In biogeography, a cosmopolitan distribution is the range of a taxon that extends across most or all of the surface of the Earth, in appropriate habitats; most cosmopolitan species are known to be highly adaptable to a range of climatic and en ...

Description

''Colacium'' is a single-celled or colonial organisms. Cells are small, about 20–40 μm, and are similar to that of ''

Euglena ''Euglena'' is a genus of Unicellular organism, single-celled, flagellate eukaryotes. It is the best-known and most widely studied member of the class Euglenoidea, a diverse group containing some 54 genera and at least 200 species. Species of '' ...

'', and are

metabolic Metabolism (, from ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the ...

with parietal, lobed

chloroplast A chloroplast () is a type of membrane-bound organelle, organelle known as a plastid that conducts photosynthesis mostly in plant cell, plant and algae, algal cells. Chloroplasts have a high concentration of chlorophyll pigments which captur ...

s each with a

pyrenoid Pyrenoids are sub-cellular phase-separated micro-compartments found in chloroplasts of many algae,Giordano, M., Beardall, J., & Raven, J. A. (2005). CO2 concentrating mechanisms in algae: mechanisms, environmental modulation, and evolution. ''An ...

, and monomorphic, small

paramylon Paramylon is a carbohydrate similar to starch. The chloroplasts found in ''Euglena'' contain chlorophyll which aids in the synthesis of carbohydrates to be stored as starch granules and paramylon. Overview Paramylon is made in the pyrenoids of ...

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. Cells of ''Colacium'' can grow a

flagella A flagellum (; : flagella) (Latin for 'whip' or 'scourge') is a hair-like appendage that protrudes from certain plant and animal sperm cells, from fungal spores ( zoospores), and from a wide range of microorganisms to provide motility. Many pr ...

and become motile, escaping from the colony as a free-swimming cell. Species: *'' Colacium arbuscula'' *'' Colacium mucronatum'' *'' Colacium sideropus'' *'' Colacium simplex'' *'' Colacium steinii'' *''

Colacium vesiculosum ''Colacium'' is a genus of algae belonging to the family Euglenaceae. It has two phases: a motile phase and a sessile phase, where it is found attached to other freshwater organisms. The genus has a cosmopolitan distribution. Description ''Co ...

References

{{Taxonbar, from=Q289498 Euglenozoa genera Taxa named by Christian Gottfried Ehrenberg Euglenozoa