Great White sharks, aside from being a brutally efficient predator, are also one of the more interesting shark species. Since they do not thrive in captivity, much of what is known about the great white’s behavior patterns has come about from years of research in the sharks’ own habitat.
Sharks have been roaming the seas for 400 million years, approximately 200 million years before dinosaurs, though great white sharks appeared in their current form around eleven million years ago. Various cultures have worshipped sharks as gods for centuries. Pearl divers in the western Pacific sought the blessings of a shark charmer prior to entering the water and tattooed themselves all over in order to pacify the shark gods. Samoans in particular worshipped great whites and hung its effigies from trees.
A great whites life span is not exactly known, though it is believed to live for approximately 20-30 years or more as an adult. A full-grown great white can grow up to twenty-one feet in length, but sightings of larger sharks have been reported. But a twenty-foot great white is not something one would ever want to encounter under water; a shark this length is eight feet wide and six feet deep. That’s as wide as a Mack truck. Their size does not hamper their movements, however. Great whites are extremely agile swimmers, their movements appearing effortless and propelled by thick, scythe-shaped tails.
Great white sharks have large, triangular, serrated teeth in their upper jaw to saw through the flesh and bones of their mammalian prey, but have slightly longer, more pointed teeth in the lower jaw to hold the prey steady (similar to how we use a knife and fork). Their Latin name, carcharadon carcharias translates to “ragged tooth”. They have rows of teeth that are folded down against the gums, and move into place, like a conveyor belt, to replace lost or broken teeth. The roots are loosely embedded in the jaw cartilage, and their teeth are held in place by fleshy gums. Great white sharks have a technique when attacking where they lift their snout up and back, dropping its lower jaw to open its mouth as wide as possible, then forcing its upper jaw forward, which can be a terrifying sight.
The great white’s hunting strategy is also unique. They hunt largely by sight and can discern shapes, though their vision is such that great whites are the only sharks that lift their head out of the water to search for prey, which is known as “sky-hopping”. Although great white sharks have been found with a multitude of strange and inedible objects in their stomachs, they are particularly fond of seals, but are also known to feed on dolphins and porpoises, sea turtles, sea birds, and squid and whale carcasses. Once thought to be solitary hunters, recent research shows that they actually establish intricate peer relationships at all ages and reside relatively amicably among each other.
Great whites hunt deep-diving seals, but many attacks on seals take place at the surface, without warning, from below or behind, often striking with such force that they leap out of the water, creating quite a spectacle when observed from above. They have been known to reach speeds of 25 mph when chasing prey. The lower jaw hits the target first, and the upper jaw bites down with enough force to shear off a sizeable piece of flesh. Great whites have an elaborate system of shock-absorbing joints protect their skull and spinal column from the power of impact.
Although great white sharks are considered the ultimate predator, they are not immune to predation themselves. Orcas, or killer whales, have actually been seen attacking and killing a great white at the Farallon Islands of the coast of California. And of course, there are humans to contend with. Over-fishing has decimated the great white shark population, as drift nets, purse-seine nets, and longlines catch millions of sharks a year, and great whites inevitably get caught up as well. Commercial fisheries also target sharks for their fins, meat, liver oil, skin, cartilage, and especially with great white sharks, jaws and teeth. The great white species is now protected by national legislation in all of Australia, Malta, Florida, California, Namibia, and South Africa.