The bull shark is an aggressive type of shark considered very dangerous to humans. Its scientific name, Carcharhinus leucas, is believed to have Greek origins, translating to “sharpen” and “nose.”
Depending on the location, the bull shark has many local names used in reference to it. Some examples of local names are Nicaragua shark and Zambezi shark. Its nickname is “pit bull of the sea.”
Bull sharks are known to attack anything found in the water, so humans must beware when there is a bull shark in the area! Fortunately, most attacks on humans by bull sharks do not lead to death.
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Habitat
Bull sharks can survive in many different habitats, including warm, shallow waters, brackish (a mixture of salt and fresh) water, rivers, and some lakes. Their tendency to frequent shallow waters close to shorelines brings them into contact with humans on a consistent basis. Usually, if a bull shark ventures up a river, it stays within 100 miles of the ocean!
Size/Color
The average bull shark is about 7 to 8 feet long and weighs between 200 to 300 pounds. The largest verified bull shark was 12 feet long! The maximum weight it can reach is 500 pounds, about the weight of a full-size piano.
Bull sharks are simply colored. They are gray on top, which fades to white below. This allows them to be camouflaged in the water.
Anatomy
Bull sharks received their name from their appearance and behavior. Their blunt snouts and habit of head-butting their prey before they attack key characteristics that earned them their name.
Diet
Bull sharks are not only predators but also carnivores (meat-eaters). They often feed using the “bump and bite technique.” The bull shark bumps the prey, possibly stunning or even killing it, allowing the bull shark to move in for the fatal bite.
Their diet includes the standard shark main dish of bony fishes, but they will also eat dolphins, squid, sea birds, and even dogs! They are always on the hunt for their next meal.
Special Adaptations
All sharks must keep salt in their bodies, or they will die. Most sharks accomplish this by living in saltwater full time. Bull sharks are unique in that they can live in salt water, fresh water, or a combination of the two. Their kidneys help them retain, or keep, water in their bodies. They also have special glands near their tails, which allow them to keep salt in their body even when swimming in freshwater sources.
When threatened by their own predators, bull sharks will basically just throw up the food in its stomach. This is called regurgitation. This technique is used to distract its attacker, hopefully allowing the bull shark to get away.
Reproduction
Bull sharks are viviparous and deliver live babies called pups after about 10-12 months of carrying them. Bull sharks deliver anywhere from 1 to 15 pups at one time. Brackish water and even freshwater lakes often become bull shark nurseries!
Scientists believe this is because many other sharks and other ocean predators cannot venture into the freshwater allowing the pups a better opportunity to mature into adulthood.
Conservation Status
Bull sharks are not a targeted species of a shark by commercial fishing vessels but often end up as bycatch. They are still prized because of their meat, skin, and oil. Bull sharks are often found in aquariums due to their ability to adapt to living in a tank environment.
Currently, the bull shark is listed as Near Threatened. Its tendency to live in such close proximity to humans makes it vulnerable to pollution and accidental netting.
Fact Attack
- The history of bull shark attacks on people has been around for centuries. In fact, a series of attacks credited to bull sharks in 1916 provided inspiration for the major motion movie, Jaws!
- Bull sharks have the biggest bite force of all shark species ~ including its famous cousin, the great white shark! However, despite their incredible bite force, the great white shark, tiger shark, and Nile crocodile are known predators of bull sharks.
- A bull shark is not a picky eater. Hippo remains have been found in bull shark stomachs!
Resources
http://www.softschools.com/facts/animals/bull_shark_facts/287/
https://www.floridamuseum.ufl.edu/fish/discover/species-profiles/carcharhinus-leucas/
http://www.nationalgeographic.com/animals/fish/b/bull-shark/
https://sharkopedia.discovery.com/types-of-sharks/bull-shark/#the-bull-shark-no-shrinking-violet
