Basking shark

The **basking shark** (*Cetorhinus maximus*) is a huge filter-feeding shark, which can grow up to the length of 40 feet (12 metres). It is the second largest shark in the world (after the whale shark). The basking shark is also called the **sunfish**, the **bone shark**, the **elephant shark**, the **sailfish shark**, and the **big mouth shark**.

## Description 
The basking shark is one of the most recognizable species of all sharks. Its large size and extended gill slits which nearly encircle the head and caudal fin together, helps distinguish it from all other species. It has a snout which is in the shape of a cone, and it has many large gill rakers made for filter feeding. Its enormous mouth extends past the small eyes and contains many small, hooked teeth. The basking shark has a very large liver that makes up to 25% of its body weight. The liver is high in squalene, a low-density hydrocarbon that helps the shark float and not sink.
The dorsal surface of the basking shark is mainly a greyish-brown colour, but can range from dark grey to almost black. The underside is usually the same colour, but is often paler and more whiter.
The basking shark has many hundreds of tiny teeth. Those teeth which are in the center of the jaws are low and triangular while those on the sides are more cone-shaped and slightly recurved. There is mainly a wide space on the center of the upper jaw which only has scattered teeth. 
The basking shark is the second largest shark in the world, only to be behind the Whale shark. The basking shark can reach lengths of up to 40 feet (12 metres), but the average adult length is 22–29 feet (6.6-8.7 m). The size at birth is believed to be between 5–6 feet (1.5-1.8 metres). The basking shark is an extremely slow-growing species and may grow to 16–20 feet (4.8–6 metres) before becoming mature.

## Habitat
The basking shark is a coastal-pelagic species, found throughout the world's arctic and temperate waters. In the western Atlantic, it ranges from Newfoundland to Florida, and southern Brazil to Argentina. In the eastern Atlantic it ranges from Iceland and Norway to Senegal, including the parts of the Mediterranean. In the western Pacific, it is found off Japan, China and the Koreas as well as western and southern Australia and the coastlines of New Zealand. In the eastern Pacific, it is found from the Gulf of Alaska to the Gulf of California and from Ecuador to Chile.

### Feeding
Along with the Whale shark and the Megamouth shark, the basking shark is one of three species of large, filter-feeding sharks. However, the basking shark is the only one that relies on the flow of water through its pharynx by swimming. The basking shark is usually seen swimming with its mouth wide open, taking in a continuous flow of water. Food is strained from the water by gill rakers in the gill slits. The basking shark's gill rakers can strain up to 2000 tons of water per hour. These sharks feed along areas that contain high densities of large zooplankton (i.e., small crustaceans, invertebrate larvae, and fish eggs and larvae). There is a theory that the basking shark feeds on the surface when plankton is common, then sheds its gill rakers and hibernates in deeper water during winter. Also, it has been suggested that the basking shark turns to benthic (near bottom) feeding when it loses its gill rakers. It is not known how often it sheds these gill rakers or how quickly they are replaced.

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