GENERAL DESCRIPTION the Great White Shark Is a Streamlined Swimmer and a Ferocious Predator

BULL SHARK

GENERAL DESCRIPTION The bull shark has a short snout that is wider than it is long (hence its name). Its belly is off-white, its top surface is gray, and the eyes are small. The first dorsal fin is much longer and more pointed than the second dorsal fin. A pup's fins have black tips, but these marking fade in the adults. The females are larger than the males. The bull shark is also know as the cub, Ganges, Nicaragua, river, Swan River Whaler, Zambezi, shovelnose, slipway grey, square-nose, and Van Rooyen's shark.

SIZE On average, adult males are about 7 feet (2.1 m) long weighing 200 pounds (90 kg). Adult females are about 11.5 feet (3.5 m) long weighing 500 pounds (230 kg).

DIET AND FEEDING HABITS The bull shark eats fish (including other sharks and rays), turtles, birds, mollusks, crustaceans, and dolphins. It will eat almost anything.

BULL SHARK ATTACKS The bull shark is one of the most frequent attacker of people, as it swims in very shallow waters where people swim and is an aggressive shark.

HABITAT The bull shark is found close to shore and can live for a while in fresh water, frequenting estuaries, rivers and lakes. It has been found up to 1,750 miles (2800 km) up the Mississippi River in the USA and 2,500 miles (4000 km) up the Amazon River in Peru. It has been found in Lake Nicaragua (Central America) and the Zambezi River (Africa).

DISTRIBUTION The bull shark is found in all tropical and subtropical oceans and seas along the coastlines and also in a few fresh water rivers and lakes.

REPRODUCTION Bull sharks are viviparous (like mammals, giving birth to live animals that were nourished by through a placenta). Litters of 1 to 13 pups are common after a gestation period of about one year. Pups are about 28 inches (70 cm) long at birth. Very young bull sharks are frequently found in protected bays near the mouths of rivers, in briny water

GREAT WHITE SHARK

GENERAL DESCRIPTION The great white shark is a streamlined swimmer and a ferocious predator with 3,000 teeth at any one time. This much-feared fish has a torpedo-shaped body, a pointed snout, a crescent-shaped tail, 5 gill slits, no fin spines, an anal fin, and 3 main fins: the dorsal fin (on its back) and 2 pectoral fins (on its sides). When the shark is near the surface, the dorsal fin and part of the tail are visible above the water.

COLORATION Only the underbelly of the great white shark is actually white; its top surface is gray to blue gray. This is useful in hunting its prey. The great white usually strikes from below and its grayish top coloration blends in with the dark water, enabling it to approach the prey unobserved.

SIZE Great whites average 12-16 feet long (3.7-4.9 m) long. The biggest great white shark on record was 23 feet (7 m) long, weighing about 7,000 pounds (3200 kg). Females are larger than males, as with most sharks. Shark pups can be over 5 feet (1.5 m) long at birth.

DIET AND FEEDING HABITS Young great white sharks eat fish, rays, and other sharks. Adults eat larger prey, including pinnipeds (sea lions and seals), small toothed whales (like belugas), otters, and sea turtles. They also eat carrion (dead animals that they have found floating dead in the water). Great whites do not chew their food. Their teeth rip prey into mouth-sized pieces which are swallowed whole. A big meal can satisfy a great white for up to 2 months.

SENSES Shark's primarily use their sense of smell followed by their sensing of electric charges. The shark's other senses, like sensing changes in water pressure, eyesight, and hearing, are less important. The great white's nostrils can smell one drop of blood in 25 gallons (100 liters) of water. (Shark nostrils are only used for smell and not for breathing, like our nostrils. They breathe using gills, not nostrils.) The sensing of minute electrical discharges in the water is accomplished by a series of jelly-filled canals in the head called the ampullae of Lorenzini. This allows the shark to sense the tiny electrical fields generated by all animals, for example, from muscle contractions. It may also serve to detect magnetic fields which some sharks may use in navigation. The great white is the only type of shark that will go to the surface and poke its head up out of the water. No one knows exactly why it does this; perhaps it is to see potential prey such as surface-dwelling sea lions.

GREAT WHITE SHARK ATTACKS Most great white attacks are not fatal. Great whites account for about 1/2 to 1/3 of all 100 annual reported shark attacks. Of these 30-50 great white attacks, only 10-15 people die.

SOCIAL GROUPS Great whites are usually solitary animals but are occasionally spotted travelling in pairs.

HABITAT Great white sharks are found near shore along most of the temperate (not very hot and not very cold) coastlines around the world.

DISTRIBUTION Great white sharks have been observed along the coastlines of California to Alaska, the east coast of the USA and most of the Gulf coast, Hawaii, most of South America, South Africa, Australia (except the north coast), New Zealand, the Mediterranean Sea, West Africa to Scandinavia, Japan, and the eastern coastline of China and southern Russia.

REPRODUCTION Great white sharks reproduce via aplacental viviparity; they give birth to 2-14 fully-formed pups that are up to 5 feet (1.5 m) long. Like all sharks, fertilization of the eggs occurs within the female. The eggs hatch within the female and are nourished by eating unfertilized eggs and smaller siblings in the womb. There is no placenta to nourish the babies - they must fend for themselves, even before birth. They swim away from the mother immediately after birth, there is no maternal care-giving.

LIFE SPAN No one knows the life span of the great white shark. Some people estimate it to be about 100 years, but this has not been proven. HAMMERHEAD SHARK

GENERAL DESCRIPTION The great hammerhead shark has a wide, thick head with the eyes at the margins. The head is indented at the center of the "hammer," which is almost rectangular in shape. This shark is gray-brown above with an off-white belly. The first dorsal fin (the large fin on the top of the shark that most people associate with sharks) is very large and pointed.

SIZE The average great hammerhead shark is up to 11.5 feet (3.5 m) long. The largest reported was 20 feet (6 m) long. These large sharks average about over 500 pounds (230 kg) but can weigh as much as 1,000 pounds (450 kg). There are 9 species of hammerhead sharks, ranging in size from about 3 feet (0.9 m) long to over 20 feet (6 m).

DIET AND FEEDING HABITS The great hammerhead is a fierce predator with a good sense of smell that helps it find its prey. The great hammerhead eats fish, including rays, and other sharks, squid, octopuses, and crustaceans. The great hammerhead has been known to be cannibalistic. Stingrays seem to be a particular favorite of the great hammerhead. It kills the ray by using its "hammer" to pin the stingray down while it takes bites from the ray's wings.

HAMMERHEAD SHARK ATTACKS Many of the hammerheads are harmless to people, but a few species, like the great hammerhead, can be very dangerous.

HABITAT The great hammerhead swims in warm and relatively warm water along the coastlines. They live over the continental shelves and the adjacent drop-off (the upper part of the mesopelagic zone) to depths of about 260 feet (80 m). DISTRIBUTION The great hammerhead is found in tropical and sub-tropical waters worldwide.

REPRODUCTION The great hammerheads are viviparous, giving birth to live young. The 20-40 pups are about 27 inches (70 cm) long at birth.

TIGER SHARK

GENERAL DESCRIPTION The tiger shark has tiger-like markings on a dark back with an off-white underbelly. Pups have spotted markings that grow together to form stripes that fade with maturity. It has a large, thick-body with a blunt snout. The first dorsal fin is much longer than the second. The caudal fin is long and pointed. There is a dermal ridge along the back between the 2 dorsal fins. Color-Adult: gray-brown on top, off-white belly, young shark: dark stripes on the back.

Tiger sharks have a special gill slit (a spiracle) behind the eyes that provides oxygen flow directly to the eyes and brain. It also has a very good sense of smell, electroreceptors sensitive to electric currents in the water, and keen eyesight. SIZE Tiger sharks grow up to 20 feet (6 m). On average they are about 10 feet (3 m) long.

DIET AND FEEDING HABITS Tiger sharks will eat fish, turtles, crabs, clams, mammals, sea birds, reptiles, other sharks, and just about anything else that they can catch alive.

TIGER SHARK ATTACKS The tiger shark does occasionally attack people and is greatly feared, but people are not sought out by sharks.

HABITAT Tiger sharks go from the surface to 1,200 feet (340 m). They swim in tropical waters worldwide and in some temperate seas. They inhabit both the shoreline and open waters, ranging perhaps up to 500 miles.

SPEED Tiger sharks swim at an average speed of 2.4 mph (3.85 kph). They can swim in fast bursts, but can only sustain these high speeds for a few seconds..

WHALE SHARK

GENERAL DESCRIPTION The whale shark is a the biggest shark and the biggest fish. It is NOT a whale. It has a huge mouth which can be up to 4 feet (1.4 m) wide. Its mouth is at the very front of its head (not on the underside of the head like in most sharks). It has a wide, flat head, a rounded snout, small eyes, 5 very large gill slits, 2 dorsal fins (on its back) and 2 pectoral fins (on its sides). The spiracle (a vestigial first gill slit used for breathing when the shark is resting on the sea floor) is located just behind the shark's eye. Its tail has a top fin much larger than the lower fin. The whale shark has distinctive light-yellow markings (random stripes and dots) on its very thick dark gray skin. Its skin is up to 4 inches (10 cm) thick. There are three prominent ridges running along each side of the shark's body. This enormous shark is a filter feeder and sieves enormous amounts of plankton to eat through its gills as it swims.

The whale shark gets up to 46 feet (14 m), weighing up to 15 tons. The average size is 25 feet (7.6 m) long It is the largest fish in the world. Females are larger than males (like most sharks).

DIET AND FEEDING HABITS The whale shark is a filter feeder that sieves small animals from the water. As it swims with its mouth open, it sucks masses of water filled with prey into its mouth and through spongy tissue between its 5 large gill arches. After closing its mouth, the shark uses gills rakers that filter the nourishment from the water. Anything that doesn't pass through the gills is eaten. Gill rakers are bristly structures (the thousands of bristles are about 4 inches or 10 cm long) in the shark's mouth that trap the small organisms which the shark then swallows. The water is expelled through the sharks 5 pairs of gill slits. The prey includes plankton, krill, small fish, and squid. The shark can process over 1500 gallons (6000 liters) of water each hour.

HABITAT Whale sharks live in warm water (near the equator) both along the coast and in the open seas. They spend most of their time near the surface.

DISTRIBUTION Whale sharks are found worldwide in the warm oceans from the equator to about ±30-40° latitude. They are not, however, found in the Mediterranean Sea.

REPRODUCTION The Whale shark was long thought to be oviparous (an egg 14 inches (36 cm) long was found in the Gulf of Mexico in 1953; this would be the largest egg in the world). Recently, pregnant females have been found containing hundreds of pups, so, Whale sharks are viviparous, giving birth to live young. Newborns are over 2 feet (60 cm) long.

Whale sharks are sexually mature at 30 years old. This is the age at which they are able to mate and reproduce.

WHALE SHARK ATTACKS Whale sharks are harmless to people and usually indifferent to divers.

LIFE SPAN It has been estimated that whale sharks may live up to 100 - 150 years.

Tiger Shark Bull Shark

Whale Shark Great White

Hammerhead

Characteristics Bull Shark Great White Hammerhead Tiger Shark Whale Shark Shark Shark General Description

Aggressive (Y/N) Reproduction

3 Facts

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