What is a Bull Shark?

The bull shark is a common carnivorous sea creature that is found across the globe in shallow waters along coasts. The shark received its name from its stocky appearance and aggressive behavior. In the wild, the sea creature lives about 16 years and grows to approximately 7 to 11.5 feet (about 2 to 3 m) long, and can weigh anywhere from 200 to 500 lbs (about 90 to 230 kg).

Known by the scientific name Carcharhinus leucas, the bull shark prefers to reside in water less than 100 feet deep (about 30 m), but can live in waters up to 450 feet deep (about 150 m). The sea creatures frequent lagoons, bays, harbors, and river mouths. During the summer, the shark migrates along coastal areas, but when the coastal waters cool down during the winter, the creatures make their way back to warmer, tropical water. Often found along the Atlantic Coast, Gulf of Mexico, and Pacific Coast, the bull shark is the only species of shark that frequent freshwater. The sea creatures have even been found in the Mississippi River.

Distinctive traits of the bull shark include its short, round nose and tiny eyes. The sharks are noted for possessing a large, triangular dorsal fin. Adult sharks are gray on their backs and have white underbellies. Young sharks have black fins, which turn lighter as they age.

At the age of 10, the bull sharks are sexually mature and proceed to mate during the summer months. Males use claspers, extensions of their pelvic fins, to release their sperm into females. The females gestate their young for up to a year, delivering as many as 13 pups. At birth, the young are 30 inches (about 74 cm) long and are self-sufficient, as they can swim on their own and are born with a mouth full of teeth.

The diet of the shark includes a variety of ocean creatures, such as bony fish, mollusks, sea birds, dolphins, and sea turtles. Near the top of the food chain, the bull shark has few natural predators, although bull shark pups can be hunted by tiger sharks, as well as sandbar sharks. Cannibalistic by nature, bull sharks can often prey on each other.

Along with tiger sharks and great white sharks, the bull shark is included in three sharks species most likely to attack people. Since bull sharks prefer shallow coastal waters along highly populated areas, they can often encounter swimmers. While the sharks do not necessarily seek out humans, they may strike at humans due to curiosity.

Bull sharks are remarkable for their ability to thrive in both saltwater and freshwater environments. Unlike most sharks, they have special physiological adaptations that allow them to regulate their body's salt concentration, enabling them to travel up rivers and inhabit lakes. They have been found thousands of miles up the Amazon River and even in Lake Nicaragua.

Bull sharks are known for their opportunistic feeding habits and have a diverse diet. They consume fish, dolphins, birds, and even other sharks. Their powerful jaws and broad, serrated teeth allow them to tackle a variety of prey, making them less specialized feeders than some other shark species that may have more restricted diets.

Bull sharks are robust and stocky, with a short, blunt snout that gives them their name. They typically have a gray top and a white underside, which helps with camouflage in the water. Adult bull sharks can reach lengths of 7 to 11.5 feet and weigh between 200 to 500 pounds, with females generally being larger than males.

Bull sharks are solitary hunters and are known for their aggressive behavior, which is partly why they are considered one of the most dangerous sharks to humans. They often hunt in shallow waters, which increases the potential for human-shark interactions. Despite their reputation, they are not indiscriminate killers and usually prefer to avoid conflict unless provoked or during feeding.

According to the International Union for Conservation of Nature (IUCN), bull sharks are classified as "Near Threatened." They face threats from habitat loss, pollution, and fishing pressures. As they often inhabit areas close to human activity, they are more susceptible to these impacts compared to other shark species that live in deeper waters.

Bull sharks are viviparous, meaning they give birth to live young rather than laying eggs. A female bull shark has a gestation period of about 10 to 11 months and can give birth to litters ranging from 1 to 13 pups. These sharks can live up to 16 years in the wild, and they reach sexual maturity at around 15 years of age.