Sharks can rouse fear and awe like no other creature in the sea. Find out about the world's biggest and fastest sharks, how sharks reproduce, and how some species are at risk of extinction....

Sharks are a group of elasmobranch cartilaginous fish characterized by a ribless endoskeleton, dermal denticles, five to seven gill slits on each side, and pectoral fins that are not fused to the head. Modern sharks are classified within the division Selachii [1] (or Selachimorpha) [2] and are the sister group to the Batoidea (rays and skates).

4 天之前 · shark, any of numerous species of cartilaginous fishes of predatory habit that constitute the order Selachii (class Chondrichthyes). Sharks, together with rays and skates, make up the subclass Elasmobranchii of the Chondrichthyes.

Sharks can rouse fear and awe like no other creature in the sea. Find out about the world's biggest and fastest sharks, how sharks reproduce, and how some species are at risk of extinction.

There are more than 500 species of sharks swimming in the world’s ocean. Yet when most people think of these cartilaginous fish, a single image comes to mind: a large, sharp-toothed and scary beast. That generalization does sharks a huge disservice, as they have far more variety than that.

There are over 400 shark species. Learn about sharks, as well as the threats this species faces, what WWF is doing to protect its future, and how you can help.

2024年11月19日 · Sharks, having evolved in Earth’s oceans more than 400 million years ago, have changed little since their emergence. Their streamlined bodies were built for speed and maneuverability in coral reef environments and the open ocean.