Carcharhinus leucas

The Bull Shark is recognised by a combination of characters including a stout body, short blunt snout and triangular serrated teeth in the upper jaw. The first two rows of teeth are used in obtaining prey, the other rows rotate into place as they are lost, broken, or worn down. Bull sharks have exceptionally powerful jaws. The dorsal and pectoral fins are quite large and they have a second dorsal fin about one third the height of the first. Bull sharks are grey above and pale below, sometimes with a pale stripe on the flank.

This species has a widespread distribution in the tropical and warm temperate waters of the world. It has a number of different names both in Australia and overseas. In Australia this species is also known as Freshwater Whaler, Swan River Whaler and River Whaler. In Africa it is called the Zambezi Shark. In Central America it often goes by the name of Lake Nicaragua Shark. It has also been known as River Shark, Cub Shark, Van Rooyen’s Shark, Slipway Grey Shark, Square Nose Shark and more…..

Bull sharks in Australia are often mistaken for other members of the Whaler family. They live in a wide range of habitats from coastal marine and estuarine, to freshwater. They have been recorded from the surf zone to a depth of 150m and are the only species of shark that are known to stay for extended periods in freshwater. Bull sharks have been reported nearly 4000km from the sea in the Amazon River system. In Australia the Bull Shark occurs from Perth, Western Australia, around the northern coastline and down the east coast to Sydney, New South Wales. It has been found in most of our river systems including the Brisbane River, Herbert River, Swan River, Clarence River, Daly River, and even Lake Macquarie.

Female Bull sharks are larger than the males. On average, adult males are about 2.1m long weighing about 90 kg. Adult females are about 2.9 m long weighing 200 kg. Studies of this shark indicate that they live for about 14 years and prefer to breed in river mouths. Litters range from 1 to 13 pups after a gestation period of about one year. Pups are about 70 cm long at birth.

“This is a shark that is very, very dangerous…”

This is a shark that is very, very dangerous. It is grouped in the top four most dangerous shark species in the world and due to it’s aggressive nature some experts consider the Bull shark to be the most dangerous, even surpassing the Great White and the Tiger Shark. Positive identification of Bull sharks involved in past attacks was made difficult due to their preference for shallow and dirty waters where the splashing of a swimmer could be mistaken for a struggling fish.

Surprisingly few people in Australia have even heard of Bull sharks, despite being responsible for a large number of attacks and deaths. Many shark experts believe that this shark is to blame for most of the deaths around the Sydney Harbour inlets in the past. Most of these attacks were previously attributed to Great Whites and Bronze Whalers. Even the Grey Nurse was mistakenly blamed for Bull shark attacks in the sixties and seventies. At certain times of the year the bull shark is the most common dangerous shark likely to be encountered by the public. There is a seasonal migration of Bull sharks along Australia’s eastern seaboard, southward in summer and northward in winter.

“His arm was taken and later … his head.”

In Africa they are known as Zambesi sharks and in a six month period during 1961 they were responsible for 3 attacks in the Limpopo River. In 1970, a fisherman was working in about 5 feet of water on his prawn net up a river, about 12 miles from the sea in Mozambique when he was attacked by a Bull shark. His arm was taken and later as he floundered under the water the shark returned and took off his head.

Pound for pound, this is the most dangerous shark in the world and it lives in all of the world’s tropical and subtropical seas, in rivers and even lakes! Definitely a good shark to learn to identify and avoid if possible.