The life of animals in fresh water is different from the life of marine life. The river, as you know, always has a weak or strong current. As a result, river dwellers have to adapt to such conditions. Small fish have learned to hide under stones, where the current is not so strong. Also, small invertebrates hide under the stones, for example, mayfly larvae have a flattened body shape, they press against the stone and cling to it with small claws, resisting the flow. Some fish have a suction cup on their abdomen, with which they stick to the bottom. In many fish, a long streamlined body, together with developed muscles, allows them to resist a strong current for a long time.
One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.