What are shark skin tooth-like scales commonly called?

What are shark skin tooth-like scales commonly called? They are commonly called dermal denticles.

Dermal denticles are tiny, tooth-like structures embedded in the skin of sharks and other cartilaginous fishes. Each denticle has a hard outer layer resembling enamel and an inner layer of dentine, making shark skin structurally similar to a surface covered in miniature teeth.

Their backward-pointing shape helps streamline water flow and reduce turbulence as the shark swims. The denticles also protect the skin and contribute to the famously rough, sandpaper-like texture of a shark. Their arrangement can vary between body regions and species, and some denticles help produce distinctive skin patterns.

“Placoid scales” is another correct scientific term, because denticles are a type of placoid scale. However, “dermal denticles” is the especially common name emphasized in shark anatomy. They should not be confused with the large, overlapping cycloid, ctenoid, or ganoid scales found on many bony fishes.