BULL SHARK Scientific Name: Carcharhinus leucas Also Known as the Zambezi shark Or the Nicaragua shark

How did the Bull Shark get its name?

-Bull sharks get their name from their short, blunt snout, as well as their pugnacious disposition (eager or quick to argue, quarrel, or fight) and a tendency to head-butt their prey before attacking. -They have well built cylindrical bodies just the same as a bull.

Geographical Distribution - Bull sharks occur in tropical to subtropical coastal waters worldwide as well as in numerous river systems and some freshwater lakes. -They have been reported 3700 km (2220 mi) up the Amazon River in Peru, and over 3000 km (1800 mi) up the Mississippi River in Illinois.

Habitat The bull shark prefers to live in shallow coastal waters less than 100 feet deep (30 m), but ranges from feet deep (1-150 m) They have a unique ability to penetrate far up rivers and hypersaline bays and stay there for a prolonged period of time.

Ecology and Breeding The typical male is around 200 pounds and 7 feet, 4 inches in length, and the average female is slightly bigger, at 285 pounds and 7 feet, 9 inches. Although there has been females caught at over 11 feet 5 inches. Living to be 18 years old or longer. Reaching maturity at 6 to 8. Counter shaded. They have very small eyes compared to other sharks. Scientist contribute this as an adaptation because they like to hunt in mercy waters and river openings. Solitary hunters, bull sharks feed on bony fishes, other sharks such as young sandbar sharks, rays, mantis shrimps, crabs, squid, sea snails, sea urchins, sea turtles, and, occasionally, garbage. Definitely an opportunistic species! They are viviparous, giving birth to 1 to 13 young in each litter after a pregnancy of 10 to 11 months. The females give birth in late spring and early summer in both hemispheres, in estuaries, river mouths, and very occasionally in freshwater lakes!! Mating takes place at the same time of the year but it is unknown as to exactly where as it has not been directly observed.

Surviving Fresh Water Bull sharks are osmoregulators. While most sharks have the same salt concentration in their blood as the water they are in. The Bull Shark has only 50% of the salt concentration in their blood. This makes them very special. The only consequence is they produce 20 times more urine when swimming in fresh water! Recent studies carried out on the freshwater sharks in Lake Nicaragua have shown that bull sharks also have a rectal gland that continuously excretes sodium and chloride, keeping their internal salts low.

Apex Predators - Teeth that are replaced throughout their life - Sensitive smell receptors - Eyes that adapt quickly to low light levels - Lateral line receptors that sense movement in the water - Electroreceptors that detect electrical fields due to the presence of prey

Impact on humans Arguably responsible for the most unprovoked shark attacks. 53 shark attacks in 2012 and many are contributed to Bull’s. They are extremely territorial and will attack other animals, including people, dogs and horses, that go into their territory. DO NOT GO INTO A RIVER, ESTUARY, OR ANY OTHER BODY OF WATER THAT ONE IS REPORTED IN!

Management In the Atlantic, bull sharks are part of the large coastal shark management group, which is overfished; commercial and recreational fishing regulations are in place for this species. In the Pacific, bull sharks are not landed in commercial and recreational fisheries and no management measures are in place for this species. Finning is prohibited. They are classified as near threatened. Bull sharks are caught in many types of fishing gear. Since they grow slowly and often only reproduce every other year their populations are shrinking.

Cites ark.htm marinebio.org/species.asp?id=83