Dermal structures giving support and protection to the body and properly considered as an exoskeleton.Scales are reduced or lacking in some fishes.Scales types include placoid scales (dermal denticles) of sharks; ganoid scales, which are very thick and hard and are arranged like paving blocks with very little overlap; cycloid scales which are thin and overlap like shingles (imbricated); and ctenoid scales which are like the cycloid type but have many tiny teeth or spines on the exposed surface.
Aggregate of small, flattened, overlapping crystals, as seen in fish scales.
thin, overlapping plates of a hard substance that protect the skin of fish. The easiest way to tell if a fish has scales is to run your finger along the side of the fish from back to front. If the fish feels smooth and slippery, it has no scales or the scales are embedded within the skin; if it feels rough and your finger catches, then it has external scales.