Sharks, the most valuable part of the marine ecosystem are the main predators of the sea. Sharks are kinds of fish that belongs to the super order Selachimorpha. Sharks have a highly streamlined body with a full cartilaginous skeleton system. Sharks are the largest species in the sea world that develop fully mature young ones. The young ones appear as a miniature version of their parents. The young ones are born with a full set of grown teeth and have the ability to swim as they come out of their mother.
There are many shark species that range in different sizes. There are about 350 (rough estimation) species of shark separated in to several orders. The fully grown sharks measures about 18 cm long. Some sharks have the size range as like humans i.e. 1.5 - 2.1 m long. And the remaining species are below 1 m long.