Fish diversity documented in Switzerland's rivers

In a major survey of Swiss rivers and streams, more than 50 different fish species were recorded. For the first time, more than one species was also found in the case of smaller types of fish such as the bullhead. In Progetto Fiumi, riverine fish were surveyed using standardized methods and both morphological and genetic characteristics were analyzed. Particularly high diversity was seen in large lowland rivers—where, however, near-natural reaches are rare.