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Basking shark

life science Maturity 5-7 Next article →

The basking shark, scientifically known as Cetorhinus maximus, is a massive marine animal. It holds the title of the second-largest living shark and fish in the world. Only the whale shark is larger than this species.

Basking Shark
Basking Shark

These sharks are recognized as one of only three shark species that eat plankton. This group also includes the whale shark and the megamouth shark. Basking sharks are cosmopolitan migratory animals. This means they are found in temperate oceans across the entire globe. They play a significant role in the marine ecosystem as large-scale filter feeders.

To feed, the basking shark uses a process called ram feeding. It swims forward with its mouth wide open to push water through its system.

BS4 small
BS4 small

The shark has a cavernous jaw that can reach up to 1.5 meters in width. As water enters the mouth, it passes over the gills. The shark possesses highly developed gill rakers, which are dark, bristle-like structures. These rakers act like a sieve to catch tiny organisms. The shark specifically targets zooplankton, such as small crustaceans called calanoid copepods. By swimming at a speed of about 2 knots, a single shark can filter up to 2,000 cubic meters of water every hour.

The anatomy of the basking shark is specialized for its lifestyle. Its skin is often greyish-brown and mottled, while the inside of its mouth is white.

Basking head
Basking head

The shark has a conical snout and a crescent-shaped caudal fin. This fin has a strong lateral keel to assist movement. Interestingly, the basking shark has the smallest weight-for-weight brain size of any shark. This is thought to reflect its relatively passive way of life. Its large liver is another vital organ. The liver can account for 25% of the shark's total body weight. This helps the animal with buoyancy regulation and long-term energy storage.

Scientists have studied these sharks for centuries. Johan Ernst Gunnerus first described the species from a specimen found in Norway. The genus name Cetorhinus likely comes from the Greek words ketos, meaning "marine monster" or "whale," and rhine, meaning "shark." The species name, maximus, is Latin for "greatest."

Throughout history, many different names were used by various zoologists. These included names like Squalus elephas and Selachus pennantii. The oldest known relatives of this family were members of the extinct genus Keasius, which lived during the Eocene epoch.

Basking sharks are known for their incredible size and movement. They typically reach lengths of 7 to 8 meters. However, large individuals have been recorded at much greater sizes. Some historical reports suggest sharks as long as 12.5 or 14 meters, though these lack strong evidence.

These sharks are highly migratory and follow plankton concentrations. Satellite tracking has shown they move thousands of kilometers during the seasons. In the winter, they often move to deeper waters, sometimes reaching depths of 1,000 meters. Some individuals have even been tracked crossing the equator to reach Brazil.

Socially, basking sharks are usually solitary animals. However, they can gather in large groups during the summer months. They often congregate where zooplankton is most dense. They can form small shoals of three or four, or much larger groups of up to 100 individuals. In some areas, such as the northeastern United States, they have been spotted in groups of up to 1,400. These summer gatherings are thought to involve courtship behaviors. They may even swim nose-to-tail in circles during these times.

Despite their intimidating size, basking sharks are not aggressive toward humans. They are very different from the great white shark, which is an active predator. While a great white has large, dagger-like teeth, the basking shark has many rows of tiny, curved teeth. These teeth are only about 2 millimeters long and are not used for hunting large prey. Basking sharks have few natural predators, though killer whales and white sharks have been known to interact with them. Humans have historically used them for food, oil, and fins, but overexploitation has led to the need for their protection.

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🖼️ Images & Media (5)
File:A Basking Shark beaten by the northerly winds - geograph.org.uk - 1553808.jpg
A Basking Shark beaten by the northerly...
File:Basking head.jpg
Basking head.jpg
File:Basking Shark.jpg
Basking Shark.jpg
File:BS4 small.jpg
BS4 small.jpg
File:Basking shark Harper's Weekly October 24, 1868.jpg
Basking shark Harper's Weekly October 24, 1868.jpg
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