why do fish have scales

Fish have scales primarily for protection and to aid in locomotion. Scales act as a shield against predators, physical damage, and harmful microorganisms. They cover the fish's soft body, helping to prevent punctures and abrasions. Additionally, scales help reduce water resistance, enabling smoother and more efficient swimming. Some scales also provide camouflage by reflecting light and blending with the environment, which helps fish avoid predators. The scales grow as the fish grows, and they are part of the integumentary system, produced from the dermis layer of the skin. There are different types of scales adapted to different fish species, each balancing protection and swimming efficiency in varying ways. For instance, some scales are hard and offer strong armor, while others are more flexible to aid movement. Some fish have specialized scales that allow water and sensory signals to pass through, maintaining their environmental awareness. Beyond protection and locomotion, scales also help deter diseases by being covered with mucus that protects against pathogens. In summary, fish have scales to protect their bodies, aid in swimming, assist in camouflage, and guard against infection.