Identification and cultivation of European Volvox spp.

Abstract

The three European species ofVolvox have repeatedly been described, also from other countries. There have remained, however, some open questions, particularly in connexion with the morphological differences betweenV. aureus andV. tertius. These species, up to now, could not readily be distinguished but can be told apart on the strength of the structure of the covering layers of the colonial envelope. The nutritional requirements have attracted little attention. The scarce statements in the literature have only been attained in investigations of a general character and needed a more thorough investigation. It was found that all three species require vitamin B12, andV. globator also vitamin B1. This species flourished only when provided with small amounts of acetate.