Question

what r placoid scales which r present in Scoliodon? giv a pic of Scoliodon.

Answer 1

Placoid scales or dermal denticles are tough scales that cover the skin. They are modified teeth like and are covered with hard enamel. Placoid scales are packed tightly together and grow with their tips facing backwards. This gives the fish's skin a rough feel. The function of these scales is for protection against predators. Placoid scales stop growing after they reach a certain size and new scales are added as the animal grows.