Great White Shark

The great white shark, also commonly referred to as great white, white shark, or white pointer, is currently the largest predatory shark. They are known for their long migration patterns as well as their breaching behavior, where they leap out of water to hunt prey.

As one of the “Big Three” sharks, along with the Tiger and Bull sharks, they are responsible for the highest number of attacks on humans. However, these sharks are not natural man-eaters and only interact with humans out of curiosity or mistake.

Description

Size: Length: Males: 11 to 13 ft (3.4 to 4.0 m) Females: 15 to 16 ft (4.6 to 4.9 m)

 Weight: Males: 1,151–1,700 lb (522–771 kg) Females: 1,500–2,450 lb (680–1,110 kg)

Teeth: They have around 300 teeth in their jaws, serrated and triangular. New teeth tend to grow back quickly to replace old ones.

Fins: Other than the characteristic dorsal fin present on the back of these sharks, they have a second smaller dorsal fin closer to their tail. They even have two pectoral fins, a single pelvic and anal fin, and a caudal tail fin.

Eyes: Their eyes, that appear larger than their body tend to be deep blue as opposed to black.

Body and Coloration: Females tend to be much larger than males. Their overall body is shaped like a torpedo with a blunt, conical snout.

Great whites have a counter-shaded appearance, with a white underside and gray upper region. This gives the shark an overall mottled appearance.

Range and Distribution

Notably, high population concentrations of great whites occur in Chile, Japan, Oceania, South Africa, the United States (Northeast and California), and the Mediterranean, including the Sea of Marmara and Bosphorus. One of the densest known populations of these sharks are seen around South Africa’s Dyer Island.

Habitat

These sharks thrive in offshore and coastal waters, with a temperature range around 54- 75 °F.

Diet

Great white sharks, being carnivores have a voracious appetite and feed on dolphins, fish, porpoises, rays, seals, sea lions, sea otters, sea turtles, small whales, some sea birds, tuna, and even other sharks. Seals appear to be the most preferred diet of these sharks as they are rich in fat and provide energy to help them swim.

Lifespan

The great white has a long lifespan, with a 2014 study indicating that they live for around 70 years or more.

Behavior

• While some remain solitary, only engaging with their companions during the mating period, certain great whites are even observed travelling in groups called shoal or school. The social group have said to be associated with their groups for long.
• Great whites are curious creatures, showing interest in their surroundings and even being one of those few shark species to poke their heads out of the water to look for their prey or any other objects passing by. This unique trait of theirs is known as spy-hopping.
• Despite their reputation as mindless killing machines, these sharks are pretty intelligent, and different sharks have shown individual personalities.
• They are a highly migratory species, with specimens traveling as far as 2,500 miles in open oceans. This seems to be based on the availability of prey.
• These sharks are fast swimmers, reaching speeds of 35 mph.
• Another significant behavior of these sharks worth mentioning is their tendency to leap at a high speed, the moment they catch sight of their prey, particularly the fast-paced seals. Due to the increased bodily movement, these sharks come out of the water partially or fully. This unique hunting trait of theirs is called breaching.

Do They Attack Humans

While the great white shark holds the record for the highest number of unprovoked attacks on humans, these attacks seem to be out of a combination of the creature’s natural inquisitiveness and their rather poor eyesight. From below, a human on a surfboard does not look to dissimilar to a seal from a shark’s point of view. Humans are not preferred prey for sharks due to their low-fat content compared to seals; however, a bite may lead to death due to blood loss due to the sheer bite force of a shark’s jaws. Juveniles are the most common attackers, owing to their lack of experience.

Great whites have been known to attack and even capsize boats as a result of being confused by the generated electric fields.

Predators

As apex predators, they have almost no natural predators. However, killer whales have been known to attack and devour the livers of these sharks. Whether this is because of feeding purposes or dietary overlap is still debated.

Adaptations

• Like most creatures adapted to life underwater, the great white’s body is streamlined, helping it to move easily in water. Its tail fins also appear stiffer, giving it a better mobility.
• Their powerful jaws and sharp teeth let them tear flesh from their prey easily.

• The counter shade coloration of these sharks makes them difficult to spot.
• They have an excellent sense of smell, capable of identifying blood up to 0.33 miles away.
• Similar to other sharks, they have a “sixth sense” provided to them by their special sensing organs, ampullae of Lorenzini, which allows them to detect electric fields.
• These sharks have a robust immune system. This has been deduced after a study was conducted in 2012 in the University of Miami on blood samples of 43 sharks taken from the coast of South Africa. These sharks were exposed to arsenic, lead, and mercury with no rise in white blood cells, implying a physiological defense against metal poisoning.

Mating and Reproduction

Very little is known about this shark’s mating habits, though it is assumed that males impregnate females by inserting their claspers into her cloaca. The fertilized eggs develop further inside the mother’s womb, and go on to eat the unfertilized eggs as nourishment, in a process known as oophagy.

Life Cycle

After gestating for 11 months, female great whites give live birth to 2-12 baby sharks, that leave their mother immediately so that they can begin fending for themselves. These juveniles develop their jaws within a month of their birth, though it takes a long time for them to reach sexual maturity. Females do so at 33 years, while males become sexually mature at 26 years.

Conservation Status

The IUCN puts the great white shark in the “Vulnerable” or “VU” category, though this is primarily because the exact population numbers remain unknown. A study performed by Barbara Block of Stanford University in 2010 indicated that there were 3500 individuals in the wild, while a study done by George H. Burgess of the Florida Museum of Natural History in 2014 estimated a much lower 2000.

Threats to the shark come mostly from humans, caused by illegal or unintentional fishing or “shark culling” in order to impede the perceived threat from them. Separate parts of the world have enacted various protection measures including the Environmental Protection and Biodiversity Conservation (EPBC) Act in Australia in 1999, a $250,000 fine and up to six months in prison in New Zealand, and a ban on baiting and chumming, cage diving, catching, feeding, or towing decoys in Massachusetts, USA in 2015.

Interesting Facts

• The notorious reputation of this shark possibly began with the Jersey Shore shark attacks that occurred between 1^st and 12^th July 1916. Five people were attacked by what was believed to be a great white shark, with only one of the victims surviving. This led to the public perception of sharks as dangerous creatures.
• In 1974, Peter Benchley would release his famous novel Jaws featuring a great white shark attacking beachgoers. This book became a bestselling novel, and its subsequent film adaptation helmed by Stephen Spielberg, increased the public fear of sharks in general and great white sharks in particular.
• The biggest great white recorded was 2.5 tons in weight and 20 ft. long. Nicknamed “Deep Blue”, she is around 50 years old and may possibly become heavier over time.
• Due to their nomadic nature, it is considered cruel to keep a great white shark in captivity. For instance, one such shark was kept in a tank in Japan, where it moved around listlessly for three days and rammed its head against the glass of the aquarium, dying shortly after.