Bony structures that cover the skin of bony fishes.

Bony structures that cover the skin of bony fishes.

• A. Scales
• B. Gills
• C. Fins
• D. Scutes

Answer: (A)

In bony fishes, the skin is protected by scales, which are dermal bone plates that grow with the fish and sit within the skin. These scales provide a protective barrier and help streamline movement in water. They come in several types (like cycloid, ctenoid, or ganoid) depending on the species, but the common feature is that they are bony structures embedded in the skin to cover it. Gills are the openings for breathing, not coverings of the skin. Fins are external appendages used for swimming. Scutes are large bony plates found on some fish (and other animals) but aren’t the typical covering for the skin of most bony fishes. Therefore, scales are the correct answer.

In bony fishes, the skin is protected by scales, which are dermal bone plates that grow with the fish and sit within the skin. These scales provide a protective barrier and help streamline movement in water. They come in several types (like cycloid, ctenoid, or ganoid) depending on the species, but the common feature is that they are bony structures embedded in the skin to cover it.

Gills are the openings for breathing, not coverings of the skin. Fins are external appendages used for swimming. Scutes are large bony plates found on some fish (and other animals) but aren’t the typical covering for the skin of most bony fishes. Therefore, scales are the correct answer.