actually, sharks have denticles. denticles are very different from fish scales because they are constructed like hard, sharp teeth to help prevent any injury to the shark's body.
spiky skin, hard scales shark
Shark skin is not soft and smooth as they it is covered in specialized scales. These scales are called placoid scales or dermal denticles.
no
Dermal denticles. Literally, "skin teeth." They are similar in structure to the teeth of a shark. See http://en.wikipedia.org/wiki/Dermal_denticle
Scales
all fish have scales, including sharks. their scales are just smaller than what you would normally think of as scales
yes it is very thick
Shark
Shark skin looks and feels like it is covered with tiny teeth. In fact, their small, rough placoid scales (also called denticles), have the same structure as sharks' teeth! Shark skin is sometimes used as sandpaper.www.vanaqua.org/education/aquafacts/sharks.html
A shark is a long-bodied fish with a cartilage skeleton, prominent dorsal fin, and scales that are tooth-like.
Shark teeth are made of dentin, a hard tissue similar to bone, covered by a layer of enamel. They have a conical shape and are constantly regenerating throughout the shark's life to replace lost or worn teeth.
Sharks are covered in placoid scales which do not grow in size as the fish does, instead more scales are added. Research has shown that scales create small vortices which serve to reduce drag.