Question

What are two general methods that fishes employ to reduce drag while swimming?

Answer 1

The area where the body meets the tail is called the caudal peduncle. The caudal peduncle also moves side to side as a fish moves its fins. This lateral motion can disrupt the boundary layer, the layer of water right next to the moving body (fish), which is crucial to reducing drag .
-when molecules of the fluid collide with Fish , The collision causes drag against moving fish, which is why many fish are streamlined in shape. Streamlined shapes work to reduce drag by orienting elongated objects parallel to the force of drag .
- Some flat-shaped fish can take advantage of pressure drag by having a flat bottom surface and curved top surface. The pressure drag created allows for the upward lift of the fish
- Some use lift powered swimming, which can be compared to flying as appendages flap like wings, and reduce drag on the surface of the appendage. Others use drag powered swimming, which can be compared to oars rowing a boat, with movement in a horizontal plane, or paddling, with movement in the parasagittal plane.