'Secrets of the Bull Shark': 20,000 teeth, 2 heads and other facts about this deadly species that inspired 'Jaws'
We may have mentioned this before, but just for good measure: sharks are perhaps some of the most fascinating predators of the ocean. Each species of shark has something unique about them and we could perhaps devote entire lives to studying them. National Geographic's Sharkfest is a great place to start. With many specials covering different aspects of sharks, the special programming is a fascinating watch should you be interested in learning more about them. The latest special, 'Secrets of the Bull Shark', focuses on one of the most dangerous species of shark. In fact, the bull shark is what inspired Steven Spielberg's 'Jaws'.
The bull shark gets its name from its short, wide, thick snout and chubby body. The bull shark reaches a maximum length of 11 feet and depending on its age, it weighs between 198 and 570 pounds. They have long pectoral fins and saw teeth. The upper part of their body is grey with a green-brown hue and their belly is white. If you notice dark spots on their fins, you will know that you are seeing a young specimen because these spots disappear as they grow. The bull shark has 50 rows of teeth and up to 350 teeth erupted in their mouth at one time. They may use over 20,000 teeth in their lifetime.
While there have been more recorded shark attacks by the great white sharks and the tiger sharks, scientists believe the bull sharks may be responsible for more but are usually misidentified. There is one particular reason that scientists believe so. Unlike great whites and tigers, bull sharks can survive both in salt and freshwater. While fish usually do not have the ability to control how their kidneys remove the salt in their bodies, ocean fish tend to expel more salt while freshwater fish tend to retain more. Bull sharks have the ability to regulate the amount of salt expelled by their bodies, depending on their environment.
This could be why the bull sharks can be found in most places, including along the Pacific coast of Central America all the way to Peru in the south. Bull sharks are also present in the Gulf of Mexico and the Atlantic Seaboard of the United States, as well as along the entire Atlantic coast of South America north of Argentina. They are also found along most of the Atlantic coast of Africa and off the coast of East Africa outside of the Red Sea. Bull sharks are especially populous in South East Asia and Oceania. Enclaves of bull sharks also live off the southwest coast of India, as well as parts of China and in the Arabian Gulf.
However, the most surprising location you can find a bull shark in is a completely landlocked lake in a golf course in Australia. The Carbrook Golf Club, located near Brisbane, Australia, lies next to the Logan River which was flooded many times in the 1990s. At some point, newborn bull sharks were swept into the lake and trapped there when the river receded. At first, shark sightings were denied thinking that the golfers were merely too drunk. However, after photos and a viral video, the golf club began capitalizing on the presence of the sharks, with a monthly "Shark Lake Challenge".
A bull shark with one head is terrifying enough, but since 2013, multiple sightings of two-headed bull sharks have been reported. Scientists at Michigan State University came across a bull shark pup with two heads in the Gulf of Mexico after it was cut out of an adult shark's uterus by a fisherman. An MRI of the specimen "revealed two distinct heads, hearts, and stomachs with the remainder of the body joining together in the back half of the animal to form a single tail". While many theorized that the mutation came as a result of the Deepwater Horizon oil spill in 2010, scientists quickly denied those allegations saying there is no connection.
'Secrets of the Bull Shark' will air again on National Geographic on August 12, at 9/8c.