TOEFL SPEAKING TASK 6: WAYS FOR FISH TO FACE FAST CURRENTS

Fish stay in the river with fast currents. There are two ways for them to overcome challenges. The first way is physical adaption. If water flow was too fast, fish cannot stay in the same place but be carried downstream. So some fish have developed special structures to overcome the strong current. For example, catfish have big muscular fins, which will help them swim against river water and let them stay in the fast flowing river. The second way is change behaviors. If the current was too fast, they are not able to capture enough food. In general, water in the center of a river flows fastest, but the water flow is slow near the bank. So the trout would spend more time near the bank because the food particles are abundant and easier to catch.