Читать книгу The World's Most Dangerous Animals - Kevin Baker Baker - Страница 6

A bull shark in Walkers Cay, Bahamas.

The Bull Shark (Carcharhinus leucas) is often considered to be one of the most dangerous sharks to mankind; some people even say that they are arguably more dangerous than even great white sharks.

They are an aggressive species of shark that prefer shallower coastal waters. What really sets these sharks apart from others is that they can survive for a while in brackish waters or even freshwater. As a result, these sharks have even been spotted in the Amazon and the Mississippi River. Although commonly found in lagoons, bays, or the mouths of rivers, it is not entirely unusual for this shark to be found as far inland as Illinois.

Typically, sharks need to have salt in their blood in order to survive. Their blood is typically as salty as the seawater around them. However, bull sharks are able to regulate the levels of salt in their blood using different organs. Therefore, they can adapt themselves to live in both salt and fresh water, although they are more commonly found in saltwater because that is where their food of choice is and their population is higher in saltwater areas, where they can reproduce easier.

The bull shark gets its name from both its stocky build and broad, flat snout, plus its very aggressive and often unpredictable behavior. When attacking, bull sharks will often initially head-butt their prey, much like a bull charging. They tend to hunt alone and are extremely territorial. They have even been known to attack racehorses in Queensland, Australia and the infamous string of attacks on the Jersey Shore in 1916 by suspected bull sharks provided the idea for the novel Jaws.

In Australia, a ferry driver once reported seeing a Chihuahua being snapped up when it came close to the edge of a river. They have even been seen leaping out of the water to snap at bats.

However, humans are not typically the bull shark’s meal of choice. They’ll eat almost anything as long as it is available: fish, turtles, other sharks and even birds occasionally. The aggressive head-butts are employed initially as a tactic to disorient their prey after slamming their whole weight (anywhere from 200-500 pounds) against them. Sometimes the head-butt alone will kill their prey outright. While their target is disoriented, the bull shark will thus gain the advantage and snatch its victim up before it can recover.

Bull sharks typically live for up to sixteen years, and they reach sexual maturity at around 10 years old. They breed in brackish water in the summer. Eggs hatch inside the bodies of the female sharks and the babies feed off of the placenta and nourishment from the mother. Gestation lasts about a year and the litters can be as big as 13 pups. These little shark babies are usually around 30 inches long and already sport a full set of teeth when fully developed. The first thing they do is to swim away from their mother, who might eat them.

Although bull sharks are one of the most dangerous species of shark, it is important to remember that there are only 16 shark attacks on average per year in the United States for example. Plus, only one shark attack every two years actually kills someone in the U.S. In fact, a person is six times more likely to be killed by a pig than a shark, which is good news for most people, except pig farmers of course.