Dormant stages of the green flagellate Volvox in a natural habitat

Reproduction and formation of resistant dormant spores in Volvox aureus (Ehr.) and V. tertius (Meyer) were studied in a biocoenosis of a transient pool in July-August 1996 and 1997. Under these conditions, the populations of two Volvox species had species-specific reproductive features. In the V. tertius population, a relatively small amount of male individuals and dormant spores (zygospores) appeared sporadically. On the contrary, in the V. aureus population, dormant parthenospores were formed, but male individuals were never observed.