The great white shark (Carcharodon carcharias) is the largest of all shark species that mainly inhabits in the coastal waters and other significant oceans. These sharks are easily recognizable due to their mammoth size and they largely rely on fish and seabirds for their diet. Great white shark is the member of genus Carcharodon and is also branded as number one to attack on humans. These species are considered to be threatened.
Great White Shark Facts For Kids
Great white sharks have long remained a mystery even to shark scientists perhaps due to the fact that they’re not successfully bred in captivity. Scientists have attempted to raise them in aquarium but not a single white shark lived more than a few days. Sometimes, it took weeks to spot one in the ocean.
White sharks are not really ‘man-eaters’ as they seldom involve in attack on humans.
They can reach a speed of 50 km/h in very short bursts.
Great white sharks have large black eye.
The largest shark ever landed was 5.9 m long, caught off Danger Point near Gansbaai.
They are often seen circling around the prey or even sea-divers.
Taxonomy Squalus carcharias Linnaeus, 1758. Europa
Other Common Names French: Grand requin blanc; Spanish: Jacqueton blanco
White sharks are fairly large sharks reaching a size of 21.3 feet (6.5 meters),with average length of about 18 feet (5.5 meters).
The white sharks are characterized by the unique disposition of their teeth, comprising serrations on both sides. They have triangular teeth.
White sharks show an obvious white coloration ranging from grey to bluish dorsal and the lateral shade. Their dorsal and ventral colorations are potentially divided on the sides.
They have perfectly adapted precaudal kneels; together with large gill slits; the first dorsal fin of white sharks is greater than the second. They possess large and lunate caudal fin, a conical snout, and with pectoral fins sided with black tips ventrally.
While great white sharks are commonly found in the cold and warm temperate regions, they also live in the oceanic tropical islands along with the other coastal marine waters. However, these sharks do not live in the waters of Indonesia, tropical Central America, and Indian Ocean. They are abundant in Australia, South Africa, and California but they are not as common as other shark species where they occur.
The largest concentration of great white shark is known to reside in United States, South Africa, New South Wales, Atlantic Northeast, Australia, Mediterranean, Chile, Dyer Island, and Japan. These animals are known to dive 1,220 metres (4,000 feet) deep into the water. Some people restricted these sharks to the coastal areas which is a wrong belief.
The great white sharks inhabiting in California are recognized as the migratory in that they travel in between California and Hawaii. This is 100 days journey. During migration they tend to dive down 300 metres (1,000 feet) deep for about 10 minutes. Some species migrate from the South African coast to the southern coast of Australia and they return in the same year. The reason of this much migration is yet to be known.
Great white sharks predominantly swim in a continental shelf sailing through relatively shallow waters, sometimes at the bottom sometimes near the surface. Some of its counterparts also live in the inshore bays and off oceanic islands. A few others cruise as deep as 4,199 ft (1,280 m). They are capable of wide excursions in the pelagic realm.
Great white sharks are often found alone because of their nomadic and solitary nature. Some are however found in pairs especially while feeding where they often aggregate in groups of 10 individuals.
White sharks also leap (breach) out of water perhaps for some other reasons. Sometimes they want to capture surface prey and they do so by breaching. White sharks often breach like dolphins, a behavior known as “Spy hopping” (when the shark exposes its head out of water pretending to search the surroundings.
White shark often involves in Repeated Aerial Gaping (RAP: a behavior in which the shark kisses the air while keeping its head out of water).
It is also observed, at times, circling around its prey or even divers and boats.
White sharks can swim very fast (50 km/h) in a short burst. It has a minimum swimming speed of 4.7 km/h.
Shark’s eyes begin to roll back into the sockets when the shark is engaged in feeding.
Individuals are segregated according to their size and weight.
These sharks are very curious but not very aggressive. It is a wanton killer.
They often raise their heads out of water to observe any activity.
Feeding Ecology and Diet
Great white shark is a tough predator as it eats many bony fish species including sharks (basking shark). It also consumes marine mammals including pinnipeds and whale carcasses; sea turtles; and they also feed on birds resting on the water surface.
While sharks most likely to feed on fish and marine mammals they also eat few invertebrates such as crabs. Although white sharks are fearsome predators in seawater, they nevertheless fall victim to killer whales (Orcas) though not too often.
These types of sharks are carnivorous and they predominantly eat fish, tuna, rays, cetaceans, dolphins, whales, porpoises, seals, fur seals, sea lions, sea turtles, seabirds, pinnipeds, and sea otters. Great white sharks are also known to eat waste materials which they usually unable to digest. They stalk their prey within a distance of 4 metres (13 feet) before the final aggression. They largely eat preys comprising energy-rich fat. The success rate is 55%. The swimming speed of these sharks is estimated at 40 km/h (25 mph).These white sharks also attack humpback whales, Risso’s dolphins, bottlenose dolphins and harbor porpoises.
Some of the species are often found feeding on dead animals.
The great white sharks are adept to detect almost every type of signal and disturbance such as vibrations, electrical pulses, smells, tastes, sights, even at extremely low intensity levels.
Smell and Taste
It has an acute sense of smell in that the 18% of its brain is engaged in picking up the information released by olfactory bulbs. The shark employs its sense of smell not only to search for food but it also plays a pivotal role in social situations. With the help of sense of smell, it discovers even the minutest traces of chemicals in water. It can also find out the source of chemicals which is few kilometers away.
It is skillful enough to identify the origin of vibrations under sea water. It observes almost all kinds of vibrations, water currents, and pressure changes. Often does it happen that water displacement generates a series of ripples which sharks are able to detect. However, white sharks mostly depend on their sight to hunt.
White shark’s embryo goes through teeth replacement many times before birth; they do so by swallowing their own teeth.
Gestation period of white sharks is not known.
Females reach the maturity age when they are in between 13.1 ft (4 m) and 16.4 ft (5 m) long. Males become mature when they reach the length of 11.5 ft (3.5 m) and 13.1 ft (4 m).
Female becomes mature at the age of 12 – 14 years while male reaches the maturity age of 9 – 10 years.
Embryos are 4 ft (1.2 m) to 5 ft (1.5 m) long birth, with the weight measuring at 25 kg (55 lb).
Great white sharks are threatened in most of the waters such as in South Africa and Australia. They are given protection in Namibia, Australia, United States, Malta, Israel, and South Africa. Australia is the only country where these species are recovered. They are listed as Vulnerable by the IUCN.
Significance to Humans
It goes without saying that white shark has the notorious reputation and is deemed to be the threat to humans. These sharks have also attacked humans in the past but they average only about three per year from 1952 to 1992. However, 80% of all shark-biting incidents occurred in the tropics where white sharks are present in small numbers. On the whole, white shark incidents are too rare to be noted. Sadly enough, humans have long hunted white sharks, some out of recreational activity while others for commercial reasons.