The Fins of FishAll fish have streamlined bodies that allow them to pass through water with ease. Part of their evolutionary design are fins, which are flat appendages made of cartilage and covered in scales. All fish have several different types of fins on their bodies that give them control as they pass through the water. Fins allow them to turn, to slow down and speed up, and to stop and hold a single position in the water.The dorsal fins are located in the center of the back of a fish and can be pointed or blunt. A pointed dorsal fin increases the fish's speed while the blunt-shaped fin offers more control to small fish in strong waters. Fish can have up to three of these fins on their backs. They are supported by two kinds of cartilage rays, spiny, and soft. A fin can contain either or both types of rays. The spiny rays sometimes also act as defensive weapons, having sharp points or even poison tips.The anal, pectoral, and pelvic fins of fish are also supported by rays. These small fins give a fish control over fine movements, allowing it to dart quickly with flashes of motion. By using these, fish can position themselves for feeding or in a school formation with other fish. The anal fin is located on the bottom part of the fish behind its anus.The pectoral fins are located on the sides of the fish, like wings on a bird. Their cartilage structure is parallel in design with the forelimbs of land creatures. The paired pelvic fins are located below and behind the pectoral fins. These are parallel to the hindlimbs of land creatures. By flapping these fins, a fish gains momentum to move itself through the water.The tail fins are also referred to as caudal fins. These allow for turning and thrusting through the water. Some fish that are able to swim very swiftly have a horizontal caudal keel fin just in front of the tail fin. This forms a kind of ridge on the tail. It adds speed and stability to the fish.According to the passage, which of the following is true about fish fins ...