The river crab, indigenous in the county of Osona, is more than just another inhabitant of the flowing rivers, it is a symbol of the untameable nature of our territory. It is the oldest freshwater crustacean in Europe and is a typical inhabitant of the rivers in our county, a species unique to the region. Its presence is so significant that even the Catalan Government (Generalitat) studies it. This crab is a symbol of the wild nature of the territory, essential as an indicator of the quality of the water. Its presence in the rivers not only enriches the aquatic ecosystem, but also reflects a healthy and well conserved environment, since it is very sensitive to pollution and changes in its habitat. It is a species in danger of extinction, making it a challenge to preserve its natural habitat and promote conservation as an integral part of the local ecosystem. The river crab, a great survivor that inhabits the waters surrounding Clarella.