Pandorina
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| Pandorina | |
|---|---|
 | |
| Pandorina sp. | |
Scientific classification  | |
| Clade: | Viridiplantae |
| Division: | Chlorophyta |
| Class: | Chlorophyceae |
| Order: | Chlamydomonadales |
| Family: | Volvocaceae |
| Genus: | Pandorina Bory de Saint-Vincent, 1824 |
| Type species | |
| Pandorina morum (O.F.Müller) Bory[1] | |
| Species | |
Pandorina is a genus of green algae in the family Volvocaceae. It is a common freshwater genus, and has a cosmopolitan distribution.[1] Along with other algae such as Volvox, Eudorina and Chlamydomonas, it is a model organism for studying the origins and evolution of multicellularity.[2]
Pandorina is composed of 8, 16, or sometimes 32 cells, held together at their bases to form a globular or ellipsoidal colony surrounded by mucilage. The cells are ovoid or slightly narrowed at one end to appear keystone- or pear-shaped. Each cell has two flagella with two contractile vacuoles at its base, an eyespot, and a large cup-shaped chloroplast with at least one pyrenoid.[1] The colonies co-ordinate their flagellar movement to create a rolling, swimming motion. Pandorina shows the beginnings of the colony polarity and differentiation seen in Volvox, with anterior cells having larger eyespots.
Asexual reproduction is by simultaneous division of all cells of the colony to form autocolonies that are liberated by a gelatinization of the colonial envelope. Sexual reproduction occurs by division of each cell of the colony into 16-32 zoogametes.[3] Sexual reproduction is isogamous.[1]
