Physiological adaptation of an Aphanomyces astaci strain isolated from the freshwater crayfish Procambarus clarkii

Physiological, epidemiological and genetical properties of an Aphanomyces astaci strain (Pc) isolated from the warm water crayfish, Procambarus clarkii, were compared to other A. astaci strains isolated from the cold water crayfish Astacus astacus, Astacus leptodactylus and Pacifastacus leniusculus. Morphology, virulence at 10 °C and several physiological characters were similar to the rest of A. astaci strains used for comparison. However, the strain Pc was able to grow faster and release zoospores at higher temperatures. This means that the Pc strain is virulent towards crayfish at higher temperatures than any previously investigated strains. The application of RAPD-PCR demonstrated that this isolate is genetically separated from all other described strains.