Volvox

Volvox

:"This article is about Volvox, a colony of microorganisms. For the rock music band with the same name, see Volvox (band)"

Taxobox | name = "Volvox"


image_width = 200px
image_caption = "Volvox aureus"
regnum = Plantae
phylum = Chlorophyta
classis = Chlorophyceae
ordo = Volvocales
familia = Volvocaceae
genus = "Volvox"
genus_authority = L.
subdivision_ranks = Species
subdivision = "Volvox aureus"
"Volvox carteri" ("V. nagariensis")
"Volvox globator"
"Volvox dissipatrix"
"Volvox tertius"

"Volvox" is one of the best-known chlorophytes and is the most developed in a series of genera that form spherical colonies. Each "Volvox" is composed of numerous flagellate cells similar to "Chlamydomonas", on the order of 1000–3000 in total, interconnected and arranged in a glycoprotein-filled sphere (coenobium). The cells swim in a coordinated fashion, with a distinct anterior and posterior – or since "Volvox" resembles a little planet, a 'north' pole and a 'south' pole. The cells have eyespots, more developed near the anterior, which enable the colony to swim towards light.

An asexual colony includes both somatic, or vegetative, cells, which do not reproduce, and "gonidia" near the posterior, which produces new colonies through repeated division. These daughter colonies are initially held within the parent and have their flagella directed inwards. Later, the parent disintegrates and the daughters invert. In sexual reproduction two types of gametes are produced. Volvox species can be monoecious or dioecious. Male colonies release numerous microgametes, or sperm, while in female colonies single cells enlarge to become oogametes, or eggs.

Habitats

"Volvox" is found in ponds and ditches, and even in shallow puddles.

According to Chamberlain (1932),

:The most favorable place to look for it is in the deeper ponds, lagoons, and ditches which receive an abundance of rain water. It has been said that where you find "Lemna", you are likely to find "Volvox"; and it is true that such water is favorable, but the shading is unfavorable. Look where you find "Sphagnum", "Vaucheria", "Alisma", "Equisetum fluviatile", "Utricularia", "Typha", and "Chara". Dr. Nieuwland reports that "Pandorina", "Eudorina" and "Gonium" are commonly found in summer as constituents of the green scum on wallows in fields where pigs are kept. The flagellate, "Euglena", is often associated with these forms. If you have a culture in the laboratory, do not throw it out when the culture disappears, because new coenobia are likely to develop from the oospores.

The individual algae are connected by thin strands of cytoplasm, called protoplasmates.

ee also

*colony (biology)

References

*Chamberlain, Charles Joseph. 1932. "Methods in Plant Histology" [http://www.biodatabase.de/Volvox] .
*AlgaeBase genus|name="Volvox"|id=43497

External links

* [http://protist.i.hosei.ac.jp/pdb/Images/Chlorophyta/Volvox/index.html Volvox] Description with pictures

* [http://www.youtube.com/watch?v=w8O4OolGcPg YouTube video of Volvox]


Wikimedia Foundation. 2010.

Игры ⚽ Поможем решить контрольную работу

Look at other dictionaries:

  • Volvox — Fichier:Volvox aureus.jpg Volvox aureus …   Wikipédia en Français

  • Volvox — aureus Systematik ohne Rang: Chloroplastida Abteilung: Chlorophyta …   Deutsch Wikipedia

  • volvox — volvóx s. m. Trimis de siveco, 10.08.2004. Sursa: Dicţionar ortografic  VOLVÓX s.m. Algă verde formată din indivizi flagelaţi, care trăieşte în colonii de formă sferică cu diametru până la un metru. [< fr., lat. volvox]. Trimis de… …   Dicționar Român

  • Volvox — Vol vox, n. (Bot.) A genus of minute, pale green, globular, organisms, about one fiftieth of an inch in diameter, found rolling through water, the motion being produced by minute colorless cilia. It has been considered as belonging to the… …   The Collaborative International Dictionary of English

  • volvox — [väl′väks΄] n. [ModL < L volvere, to roll (see WALK) + ox (as in atrox, fierce)] any of a genus (Volvox, family Volvocaceae) of multicellular, free swimming, flagellated green algae whose cells form a pale green globular colony that rolls… …   English World dictionary

  • Volvox — Volvox, eine Art Infusionsthierchen …   Pierer's Universal-Lexikon

  • Volvox — L. (Kugelalge, Kugeltier), Gattung einzelliger, Chlorophyll führender und daher grün gefärbter, aktiv beweglicher Organismen, die kugelförmige Kolonien (Cönobien) bilden. Die Gattung wird zu den Geißeltierchen (Autoflagellaten), aber auch zu den… …   Meyers Großes Konversations-Lexikon

  • Volvox — L., Algengattg. der Chlorophyzeen, hohlkugelige, aus Tausenden von Einzelzellen bestehende, mittels Zilien bewegliche Kolonien von 0,5 mm Durchmesser; zuzeiten massenhaft in Teichen auftretend, z.B. V. globātor L., früher als Kugeltierchen zum… …   Kleines Konversations-Lexikon

  • volvox — 1798, from L. volvere to roll (see VULVA (Cf. vulva)) …   Etymology dictionary

  • Volvox — carteri …   Wikipédia en Français

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”