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
Oltmanns, 1904, orth. bot.
Families
Synonyms
  • Volvocida Francé, 1894, orth. zool.
  • Phytomonadina Blochmann, 1895
  • Chlamydomonadales Fritsch in West & Fritsch, 1927

In taxonomy, the Volvocales, also known as Chlamydomonadales, are an order of flagellated or pseudociliated green algae, specifically of the Chlorophyceae.[1] Volvocales can form planar or spherical colonies. These vary from Gonium (four 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.

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 flagellated gametes of equal size) to oogamy (one gender produces a much larger, nonmotile 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

Scientific references

Scientific databases

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.