The Characteristics of Grayling Biotopes

Abstract

The present study analyzes the biotopes of the grayling (Thymallus thymallus Linnaeus, 1758) in the Elbe and Danube river basins from the viewpoint of hydro- graphy, temperature, chemical and saprobic indicators. A wider ecological valency of this species was proved, not yet fully utilized. Further, the grayling is an important bioindicator of the trend in the quality of water-courses in submoutainous areas, uplands and, under the dams, also of the lowlands. The characterized conditions in the grayling biotopes are a starting point for veterinary medicine when improving diagnosis of diseases and their prevention. Along with river management they reveal great