Sharks

Sharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago. Since that time, sharks have diversified into 440 species, ranging in size from the small dwarf lanternshark, Etmopterus perryi, a deep sea species of only 17 centimetres (6.7 in) in length, to the whale shark, Rhincodon typus, the largest fish, which reaches approximately 12 metres (39 ft) and which feeds only on plankton, squid, and small fish by filter feeding. Sharks are found in all seas and are common down to depths of 2,000 metres (6,600 ft). They generally do not live in freshwater, with a few exceptions such as the bull shark and the river shark which can live both in seawater and freshwater. They breathe through five to seven gill slits. Sharks have a covering of dermal denticles that protects their skin from damage and parasites, and improves their fluid dynamics so the shark can move faster. They have several sets of replaceable teeth.

In Sci-Fi
The 1986 animated feature Transformers: The Movie introduced a series of robotic animals based on sharks called the Sharkticons.

In the 2005 NBC television series Surface, a group of fisherman caught a great white shark off the coast of Australia. However, before they could reel it in, a mutant form of pliosaur emerged from the depths of the ocean and bit the shark in half. Moments later, it broke the surface of the water and swallowed the entire fishing boat and it's crew.