Volvocales

Volvocales
(A) Gonium pectorale, (B) Eudorina elegans, (C) Pleodorina californica, and (D) Volvox carteri
Scientific classification
Domain:	Eukaryota
Kingdom:	Plantae
Division:	Chlorophyta
Class:	Chlorophyceae
Order:	Volvocales
Families
Dunaliellaceae Chlamydomonadaceae Spondylomoraceae Volvocaceae Haematococcaceae Asteromonadaceae Tetrabaenaceae Astrephomenaceae Phacotaceae Characiosiphonaceae Characiochloridaceae
Synonyms
Chlamydomonadales Volvocida

In taxonomy, the Volvocales, also known as Chlamydomonadales, are an order of flagellate or pseudociliate green algae, specifically of the Chlorophyceae^[1] . Volvocales can form planar or spherical colonies. These vary from Gonium (4 to 32 cells) up to Volvox (500 cells or more). Each cell has two flagella, and is similar in appearance to Chlamydomonas, with the flagella throughout the colony moving in coordination^{[citation needed]}.

Both asexual and sexual reproduction occur. In the former, cells divide until they form new colonies, which are then released. In the smaller forms typically all cells are involved, but larger forms have anterior vegetative and posterior reproductive cells. Sexual reproduction varies from isogamy (both genders produce flagellate gametes of equal size) to oogamy (one gender produces a much larger, non-motile gamete).

The classification of the Volvocales varies. Very often they are taken to include the orders Chlamydomonadales and Dunallielales, which contain closely related unicellular flagellates, as suborders.

References

1. ^ See the NCBI webpage on Chlamydomonadales. Data extracted from the "NCBI taxonomy resources". National Center for Biotechnology Information. ftp://ftp.ncbi.nih.gov/pub/taxonomy/. Retrieved 2007-03-19. 

External links

Scientific references

• PubMed references for Chlamydomonadales
• PubMed Central references for Chlamydomonadales
• Google Scholar references for Chlamydomonadales

Scientific databases

• NCBI taxonomy page for Chlamydomonadales
• Search Tree of Life taxonomy pages for Chlamydomonadales
• Search Species2000 page for Chlamydomonadales
• Guiry, M.D.; Guiry, G.M. (2008). "Volvocales". AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org/browse/taxonomy/detail/?taxonid=4541.