These scales also help the shark swim more quickly because their streamlined shapes helps decrease the friction of the water flowing along the shark's body, by channeling it through grooves. Also, the shark's skin is so rough that contact with it can injure prey. All of the spines of the denticles point backwards (towards the tail), so it would feel relatively smooth it you moved your hand from head to tail (but rough the other way).

COLOR

Sharks are mostly drably countershaded. This means that the top and bottom sides are colored differently serving to camouflage the shark from multiple perspectives. The top (the dorsal side) is considerably darker than the belly (the ventral side). When the shark is viewed from above, its dark top surface blends into the dark ocean depths or ocean floor. When viewed from below, the light-colored belly blends in with the light above. This helps the shark hunt in a stealthy manner, enabling it to sneak up on prey undetected.



Bottom-dwelling sharks (like the angelshark) are camouflaged to blend into the sand, mud, and rocks of the ocean bed.



THICKNESS

Sharks have very thick skin. Whale sharks have especially thick skin, up to 4 inches (10 cm) thick.



