Volvox

These are spherical colonies of green algae, phylum Chlorophyta. This genus, Volvox, has colonies comprising in excess of 500 small, green, bi-flagellate cells more or less equally spaced on the surface of a hollow globe of mucilage. Large colonies may exceed 1 mm in diameter. They are frequent in still or slow flowing freshwaters. Volvox is one of the most beautiful objects to be found in freshwater and is large enough to be easily visible to the naked eye.

Its ability to reproduce asexually is well documented and usually a culture of Volvox will adequately demonstrate that most larger colonies have daughter colonies developing within. Many textbooks will mention that even these daughters propagate grand-daughters inside, before even they themselves are borne - such an event is seldom seen. In really ripe, mature colonies the daughters swim free within the lumen of the parent, spinning on variable axes as the parent spins independently on its own axis. Very occasionally the grand-daughters swim free and then the viewer is presented with a true miracle of movement (see above).

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