Bull Sharks: The Coastal Predator You Didn’t Expect
Great whites and tiger sharks often steal the spotlight, but bull sharks may actually be the most dangerous of all. Unlike other sharks, bull sharks frequently swim close to shore, where humans swim.
Scientific Name and Other Nicknames
The bull shark’s scientific designation is Carcharhinus leucas. Around the world, it is also known as the Ganges shark, Zambezi shark, ground shark, shovelnose, freshwater whaler, swan river whaler, or slipway grey.
Distribution and Habitat
Bull sharks inhabit warm waters globally. In the Atlantic, they range from Massachusetts to Brazil. In the Indian Ocean, they are found from Africa and India to Vietnam and Australia. They avoid cold Pacific waters but have been spotted from Baja, California, down to Ecuador.
Freshwater Survival
Remarkably, bull sharks are one of only two shark species capable of living in freshwater, alongside the rare river shark. They are commonly found in rivers and lakes, traveling thousands of miles upstream. For instance, they have been reported 2,200 miles up the Amazon River and as far as Illinois on the Mississippi River.
Human Interaction and Danger
According to the International Shark Attack File (ISAF), bull sharks rank third in unprovoked attacks on humans, with 77 incidents and 25 fatalities as of 2008. Tiger sharks rank second, and great whites first. Many attacks by bull sharks may go unreported, especially in developing regions where these sharks frequently swim.
Physical Characteristics
Bull sharks are named for their stout body, rounded nose, and aggressive temperament. Unlike some other sharks, they lack an interdorsal ridge between their two dorsal fins. Juveniles may have dark-tipped fins, which fade as they mature. Bulls have a dark-to-light gray coloration with a white underbelly and smaller eyes suited to murky nearshore waters.
Teeth and Jaw
The bull shark’s jaw contains hundreds of wide, triangular teeth, about 1.5 inches long, heavily serrated and ideal for tearing flesh.
Size and Sexual Dimorphism
Bull sharks are shorter than great whites, with adults reaching up to 11 feet (3.3 m) and 500 pounds (226 kg). Females are larger, averaging 7.8 feet (2.3 m) and 285 pounds (129 kg), while males reach about 7.3 feet (2.2 m) and 210 pounds (95 kg). Females grow larger because they live longer and continue growing throughout their lifespan.
