Abstract
The representatives of the genus Compsopogon Montagne in Bory et Durieaux (Rhodophyta) are basically tropical or subtropical algae. In central Europe they are only found in aquaria and in water bodies affected by thermal effluents, like the species C. aeruginosus (J. Agardh) Kützing in the Pulkau River (Austria), a tributary of the Dyje /Thaya River (Austria, Czech Republic). The first observation of this species was made in 2007 in the Pulkau River. In autumn 2010 the species was also observed at lower densities in an approximately 20 km section of the Dyje/Thaya River between the mouth of the Pulkau River (A) and the Nové Mlýny Reservoir (CR). Recently, the species was found also in Skryjský Brook, a tributary of the Jihlava River, below the cooling water effluent from the Dukovany Nuclear Power Plant, South Moravia, Czech Republic. This is the second finding of representatives of the genus Compsopogon in rivers in central Europe.