It is a fish species that lives in freshwater rivers in Europe and belongs to the Cyprinidae family. Known for its unique tentacles, which are located on both sides of the fish's mouth and are used to detect food and sense the surrounding environment. The body is usually elongated, with flattened sides and colors ranging from olive green to dark brown. The abdomen is usually silver white. Mainly inhabiting clear and flowing rivers, especially in areas with gravel or sandy bottoms. It is a benthic fish that feeds on benthic invertebrates, including insect larvae, crustaceans, and mollusks. Widely distributed in Europe, it has high requirements for water quality. It is also a target fish species for fishing enthusiasts.

It is a large freshwater fish species unique to North America, belonging to the Cyprinidae family. Large in size, it is one of the largest fish species in freshwater. Flat body, wide head, with a large mouth filled with tiny teeth, adapted to their omnivorous habits of feeding on plankton, insects, crustaceans, and other small fish. Widely distributed, it can be found in rivers, lakes, and reservoirs from the prairie provinces of Canada to the Midwest and Southern states of the United States. I like to inhabit water bodies with slow water flow and sediment at the bottom. Such environments are rich in food and suitable for growth and reproduction. It is one of the favorite target fish species for fishing enthusiasts.

It is a precious freshwater fish that lives in the Danube River basin and its tributaries. Belonging to the Salmonidae family, it is known for its enormous size and unique ecological habits. The body is slender, with a silver gray color and dark markings that help camouflage in rocks and sediments in rivers. The head is large and has sharp teeth, adapted to the predatory habits of fish and other aquatic animals as the main food. It is an important member of the Danube River Basin ecosystem and plays a crucial role in maintaining ecological balance. Currently listed as an endangered species. It is a natural heritage of the Danube River Basin and a focus of attention for fishing enthusiasts and nature conservationists.