Bull Shark Amazing Facts

Today on Animal Facts we’re discussing Bull Sharks.

These sharks, along with white sharks and tiger sharks, are considered among the top three most dangerous sharks to humans, however, we feel it’s important to note that a person is more likely to get struck by lightning, drown while swimming, or die from a dog attack than be killed by a shark. Bull sharks live in coastal tropical and temperate marine waters around the world.

What sets these sharks apart from others, however, is their ability to live in freshwater. They can live in freshwater because they’re able to adjust the way their kidneys process salt and retain salt in their bodies. Most sharks can’t do this, so, when they enter freshwater, their cells lose their salt to the surrounding freshwater through osmosis and basically explode.

This doesn’t happen to bull sharks, so bull sharks frequently enter freshwater, and their babies are often born in low salinity areas where other predators, like other sharks, are unable to reach them. Bull sharks have been observed up the Mississippi River as far north as Illinois. There is also a population of bull sharks living in Lake Nicaragua. In fact, these sharks are believed to be the culprits behind the attacks that inspired “Jaws” because the attacks happened in freshwater! So the great white might have gotten slighted on that media depiction - or maybe the bull Shark did since everyone seems to know about white sharks! Bull sharks average seven and a half feet (2.3m) in length though females are larger than males and have been observed up to 13 feet (4m) long.

They’re generally found in turbid, or murky, water up to 100 feet (30m) deep, though they may dive to nearly 500 feet (150m). During the warmer parts of the year, they may move to temperate waters and then return to tropical waters as the temperature drops. Bull sharks are generalists meaning they take a variety of prey items. These can include fish from catfish to rays, sea turtles, sea birds, mammals like dolphins, crustaceans, and more all the sharks that have had their bite force measured, bull sharks currently hold the top spot for strongest jaws among sharks which likely helps them chomp through tougher prey. In turn, bull sharks may be taken by humans as well as other sharks like tiger sharks.

This is likely a contributing factor to why their young are born in low salinity environments where other sharks are unable to reach them. Like lemon sharks, bull sharks are requiem sharks and give birth to live young. They reach reproductive maturity between 10 and 20 years of age with females taking longer than males. They have multiple partners and males bite the females while mating which often results in scarred fins in females. Gestation in bull sharks lasts ten to eleven months and up to thirteen pups may be born at a time. If they can survive predation, bull sharks may live to be anywhere from 20 to more than 30 years old!