Is this a shark? And, if yes, what kind of shark is it?
On this and linked pages you will find general and simplified information about the class of cartilaginous fishes. Specific information about the orders, families and genera of sharks with their typical characteristics give you an overview of the family tree of sharks and facilitate the identification of an unknown shark.
The class of cartilaginous fish separated from the class of bony fish about 440 million years ago. The over 1,200 species of cartilaginous fish are divided into sharks, skates, rays and chimeras. Sharks and rays occur in the sea from the deep sea to the shallow water zones. Some species also live temporarily or permanently in freshwater. Chimeras live primarily in the deep sea. Most species are hunters, but some feed on plankton. Due to their slow reproduction, well over half of all cartilaginous fish are on the Red List of Endangered Species of the IUCN.
The diverse forms of cartilaginous fishes
A - Chimaera (© BluePlanetArchive.com). B - Whale shark (© Simon Pierce). C - Tiger shark (© BluePlanetArchive.com). D - Angel shark (© BluePlanetArchive.com). E - Manta ray (© BluePlanetArchive.com).