Bull Shark

Bull sharks are large and stout, with females being larger than males. The bull shark can be up to 81 cm (2 ft 8 in) in length at birth. Adult female bull sharks average 2.4 m (8 ft) long and typically weigh 130 kg (290 lb), whereas the slightly smaller adult male averages 2.25 m (7 ft) and 95 kg (209 lb). While a maximum size of 3.5 m (11 ft) is commonly reported, a single record exists of a female specimen of exactly 4.0 m (13 ft). A 3.25 m (10.7 ft) long pregnant individual reached 450 kg (990 lb). The maximum weight of the 4.0 m (13 ft) long pregnant female can be over 600 kg (1,300 lb), ranking it among the largest of the requiem sharks. Bull sharks are wider and heavier than other requiem sharks of comparable length, and are grey on top and white below. The second dorsal fin is smaller than the first.

The bull shark is commonly found worldwide in coastal areas of warm oceans, in rivers and lakes, and occasionally salt and freshwater streams if they are deep enough. It is found to a depth of 150 m (490 ft), but does not usually swim deeper than 30 m (98 ft). In the Atlantic, it is found from Massachusetts to southern Brazil, and from Morocco to Angola.

The bull shark is a marine apex predator, capable of taking a variety of prey. The bull shark's diet consists mainly of bony fish and small sharks, including other bull sharks, and stingrays. Their diet can also include turtles, birds, dolphins, terrestrial mammals, crustaceans, and echinoderms. They hunt in murky waters where it is harder for the prey to see the shark coming. Bull sharks have been known to use the bump-and-bite technique to attack their prey. After the first initial contact, they continue to bite and tackle prey until the prey is unable to flee.

The bull shark is a solitary hunter, though may briefly pair with another bull shark to make hunting and tricking prey easier.

The bull shark is the best known of 43 species of elasmobranch, across 10 genera and four families, to have been reported in fresh and/or brackish water. Other species that enter rivers include the stingrays (Dasyatidae, Potamotrygonidae and others) and sawfish (Pristidae). Some skates (Rajidae), smooth dogfishes (Triakidae), and sandbar sharks (Carcharhinus plumbeus) regularly enter estuaries.

Bull sharks mate during late summer and early autumn, often in bays and estuaries. After gestating for 12 months, a bull shark may give birth to 1 to 13 live young.

They are viviparous, born live and free-swimming. The young are about 70 cm (27.6 in) at birth. The bull shark does not rear its young; the young bull sharks are born into flat, protected areas. Coastal lagoons, river mouths, and other low-salinity estuaries are common nursery habitats.

Since bull sharks often dwell in very shallow waters, are found in many types of habitats, are territorial by nature, and have no tolerance for provocation, they may be more dangerous to humans than any other species of shark. Bull sharks are one of the three shark species (along with the tiger shark and great white shark) most likely to bite humans.

One or more bull sharks may have been involved in the Jersey Shore shark attacks of 1916. While it is a common misconception that these attacks were the inspiration for the novel Jaws, its author Peter Benchley has stated this is not the case. The speculation that bull sharks may have been responsible is based on two fatal bites occurring in brackish and fresh water.