What's a shark? Is a shark a fish? They seem trivial, but in reality they're not trivial at all. As you know, sharks are fish...but their skeleton is different from that of giltheads and tuna! They belong to the group of cartilaginous fish (class Chondrichthyes) and are characterized by a skeleton completely of cartilage: the bone is completely absent in this group of animals!
BETA
M****o
