How are pectoral fins on a shark different than those on a reef fish?
Sharks have relatively inflexible pectoral fins that guide them during up and down and forward motion and through turns. Reef fish use their pectoral fins for precise motion control and can turn and even back up using their pectoral fins.Evolutionary DifferencesSharks and bony fishes took different evolutionary paths about 350 to 400 million years ago. When a shark moves through the water, the pectoral fins allow it to swim upward and can provide lift during level swimming. If a shark stops swimming, it sinks. Reef fishes have swim bladders that keep them neutrally buoyant, leaving their pectoral fins available for more complex maneuvering.ManeuverabilityReef fishes have evolved into many different forms. In general, they have highly flexible pectoral fins that allow them to explore crevices and caves in coral reefs. Reef fish use this maneuverability to find food and shelter in the coral reef. They can even use their pectoral fins to swim backward when needed. Reef fish pectoral fins
