Image of hypnozygotes (zygospores) in a Volvox colony, likely Volvox globator, based on the small number of zygotes and robust spines of zygotes (pers. comm. by Hisayoshi Nozaki).

After fertilization, the Zygote produces a thick spiny cell wall. This functions as a "resting" stage. The Volvox genus is fairly common in warm water ponds and lakes rich in nitrogen. A very large motile colony containing between 500 and 60,000 Chlamydomonas like cells on the edge of a shell of mucilage. Phototactic.

Collected from the lower pond at Bodega Resort, Galiano Island, British Columbia, Canada, July 25-2003.