Pleodorina

Pleodorina is a genus of colonial green algae in the family Volvocaceae. It occurs in freshwater habitats and has a cosmopolitan distribution.

== Description == Pleodorina consists of motile colonies of 32 to 128 cells, which are arranged in the periphery of a gelatinous matrix, forming a hollow sphere. Cells are differentiated into those that are purely vegetative in character (somatic cells) and those capable of dividing to form daughter colonies (reproductive cells). Somatic cells are smaller than reproductive cells and are located in the anterior part of the colony, while reproductive cells occupy the rest of the colony. In one species Pleodorina sphaerica, somatic cells are also randomly distributed amongst reproductive cells. In some species, individual cells are surrounded by a gelatinous sheath. All cells are biflagellate (with two equal flagella), and have a cup-shaped chloroplast, an stigma, many contractile vacuoles, and one to many pyrenoids.