Eudorina

The Volvocaceae are a family of unicellular or colonial biflagellates, including the typical genus Volvox. The family was named by Ehrenberg in 1834, and is known in older classifications as the Volvocidae. Originally it included all the colonial forms here grouped as the Volvocales, but since has been restricted to the spherical colonies, which form as a flat plate of cells and undergo a process of gastrulation before being released. These organisms have been studied by geneticists who hope that they may shed light on gastrulation in the development of other organisms, including humans.

Eudorina colonies are composed of 16 or 32 spherical, biflagellate cells loosely aggregated into a globular shape within a mucilage envelope. In some species the mucilage sheaths extend around each individual cell. The cells are spherical or ovoid and each have two equal flagella with contractile vacuoles at the base, an eyespot, and a large cup- shaped chloroplast with at least one pyrenoid. The eyespots of the anterior cells are larger than those of the posterior cells.