12 Facts About Great White Sharks

iStock
iStock

In 1974, Peter Benchley released Jaws, a horror novel that sold 20 million copies, spawned an iconic film—and catapulted the great white shark (Carcharodon carcharias) to infamy. Although the book brought him fame and fortune, Benchley came to rethink its negative portrayal of great whites: The author-turned-conservationist said in 1995 that if he was writing his book then, “The shark … could not be the villain; it would have to be written as the victim.” The great white is now classified as a vulnerable species. Read on to find out why the truth about Carcharodon carcharias is often stranger—and always more compelling—than the fiction that obscures it.

1. EYE-ROLLING IS A DEFENSE MECHANISM.

Many sharks protect their eyeballs with a pair of clear lid structures called nictitating membranes, which act like protective, transparent eyelids. But not great whites—they don't have the membranes. Instead, their eyeballs roll backwards into the skull reflexively when a shark bites into a thrashing victim [PDF]. This exposes the sclerotic coat, a fibrous tissue that surrounds the eye.

2. SOME REPORTS ON THEIR SIZE ARE KIND OF FISHY.

The great white is a huge fish, no question—but some claims about its maximum size are probably exaggerated. In 1870, one zoologist measured the disembodied jaws of a large adult and estimated that the whole shark must have been 36.5 feet long. But a modern reevaluation—in which the jaws were compared to those from other dead sharks—showed that the creature’s actual length was probably about 16.5 feet, and the reports of the giant shark were likely a printer’s error.

And then there's the Cojímar specimen, a great white captured and killed near Cuba in the early 1940s. Those who saw it in person said the fish was 21 feet long and weighed 7100 pounds. Since then, the claim has been disputed by fish experts who, using an available photo, calculated that the animal’s real length was also in the ballpark of 16 feet. According to biologist Jose Castro’s book The Sharks of North America, the largest great white “believed to have been measured reliably” stretched 19.6 feet long. When it comes to weight, big males have been measured weighing up to 2819 pounds while the largest female weighed 4343 pounds.

3. GREAT WHITES ARE CLOSELY RELATED TO MAKOS.

According to a 2016 paper, there are 509 species of shark divided into nine orders and 34 families. Great whites belong to the lamnidae family, which contains only four other species: the porbeagle, the salmon shark, the longfin mako, and the shortfin mako. All five sharks have conical snouts, eyes that look solid black, and lengthy gill openings. They share a couple of other things as well—including a method for trapping body heat.

4. THEY CAN STAY WARM IN FRIGID WATER.

Most shark species have no direct control over their body temperatures; they're about as hot or cold as the water they’re swimming in. But there are a handful of species—the entire lamnidae family included—that are endothermic, meaning they can consistently maintain high body temperatures even in cold water.

The great white and its relatives have their powerful muscles to thank for this talent. The muscles naturally produce heat as they contract, warming up blood in that area, which is then redistributed to other parts of the body. This allows great whites to keep their core body temperature as high as 25 degrees (Fahrenheit) warmer than the ambient water, which means they can thrive in bitterly cold places. And when muscles are kept warm, they work more efficiently, so great whites can swim faster and farther than many other sharks. On the flip side, great whites need to consume a huge amount of calories in order to keep their body temperatures up.

5. NOT ALL GREAT WHITES GO AFTER THE SAME FOODS.

Great whites have varied diets and not all individuals share the same food preferences. But in general, younger sharks mostly eat fish and squids while older, larger sharks tend to go after big targets like marine mammals. Catching small fish and biting into fatty seals are, of course, two very different tasks. This explains why juvenile white sharks have narrower teeth than adults do—the better to pierce the skins of slippery fish. Living sharks of every species possess multiple tooth rows and are constantly replacing old chompers with brand new ones. As a great white matures, its incoming teeth become broader, serrated, and triangle-shaped, allowing great white adults to tear large chunks of meat off their victims.

6. GREAT WHITES CAN GET AIRBORNE.

Fatty, calorie-rich pinnipeds like seals and sea lions are common prey for large great whites, which typically attack from below in an explosive burst. The top speed of a great white is over 20 miles per hour, and during seal hunts, they can burst completely out of the water—a feat known as breaching—which leads to the successful capture of a pinniped 40 to 55 percent of the time, depending on lighting and other variables.

7. THEY DINE ON THE WORLD’S BIGGEST FISH.

In the 1960s, a 14.7-foot great white shark was captured near an Australian whaling station and, when it was dissected, two mysterious bones were found in its stomach. They were later identified as vertebrae belonging to an adult whale shark that was estimated to be 28 feet long. These filter feeders can grow to be 40 feet long and weigh at least 7 tons; experts now think that great whites are scavenging on floating whale shark carcasses rather than hunting the fish.

8. ATTEMPTS TO PUT THEM IN CAPTIVITY HAVEN’T GONE WELL.

Certain sharks thrive in aquariums; great whites don’t. Every single great white that’s been placed in captivity has either died or been released after a brief stay. The Okinawa Aquarium, Sea World San Diego, and the now-defunct Marineland of the Pacific are among the facilities which experimented with captive white sharks at some point or other. At the Monterey Bay Aquarium, one specimen spent a record-breaking six months living in a million-gallon tank. Once she began stalking other display fish, however, she was set free. Several different factors make great whites ill-suited for captivity. To breathe, the animals must be in constant motion to push water over their gills, and aquariums don’t always offer enough space for this. Other issues include the species’ famously large appetite and its tendency to run into glass walls.

9. DESPITE MYTHS TO THE CONTRARY, GREAT WHITES CAN GET CANCER.

There’s a myth that great whites and other sharks are immune to cancer, which has had some unfortunate real-world consequences. Assertions that shark cartilage is an edible cancer cure has led to mass harvesting of the vulnerable fish.

For the record, clinical tests have shown that ingesting shark cartilage in no way treats any form of cancer. Cancer has been documented in more than 20 shark species, including the great white: The first reported instance of a tumor-plagued great white was announced in 2015.

10. THEY TRAVEL VAST DISTANCES.

The great white inhabits many of the world's oceans, but they're most often found in waters with surface temperatures from 59°F to 72°F. The species also migrates seasonally. Some travel from South Africa to Australia and back every year. Other great whites cross the Atlantic, making long treks between Cape Cod, Massachusetts and the Azores, 2300 miles away. And each winter, scores of them leave Californian waters for a point researchers have nicknamed “the white shark café.” Located halfway between Hawaii and Mexico, this region doesn’t appear to offer much in the way of food, but the sharks remain there from April to July. Data from tagged great whites tells us that the males go on rapid, deep dives multiple times per day while hanging out in this area. Nobody knows why the white shark café is such a hot destination—but it might be a place where the fish gather to breed.

11. ORCAS PREY ON THEM.

When great whites get knocked upside-down, they freeze up and exhibit “tonic immobility,” a state of semi-consciousness. There’s at least one animal that can exploit the vulnerability. On October 4, 1997, an orca was seen barreling towards a great white shark (which measured 9 to 13 feet long) near one of California’s Farallon Islands. A human onlooker filmed the orca dragging the stunned fish around on its backside. Eventually, it let go [PDF], and then ate the dead shark's liver.

Between May and the end of June 2017, the bodies of four white sharks—all missing their livers—washed onto South African beaches. All four deaths have been attributed to orcas. A great white’s liver is high in fat and loaded with nutrients, which may account for the orcas’ interest in singling it out for consumption. One of the sharks had its testicles and stomach missing as well.

12. DO THEY REALLY MISTAKE PEOPLE FOR SEALS? PERHAPS NOT.

Though shark-on-human attacks are rare, most of the time, when you do hear about an attack, a great white is behind it. Since 1580, Carcharodon carcharias has been positively identified in at least 314 unprovoked attacks on humans (80 of them fatal). No other shark species is credited with even half as many.

According to one common explanation, great whites attack humans because they mistake them for pinnipeds. The argument goes that, when viewed from below, a person on a surf board projects a seal-like silhouette.

While this is a popular idea, it leaves some critical things unexplained. First of all, great whites have proportionally large eyes by shark standards—and acute vision to boot. Also, the big fish strike seals with tremendous force at great speed; by comparison, the sharks usually move at a slow, deliberate pace when approaching people. And in the vast majority of attack incidents, a great white will deliver a single bite and then leave without consuming the victim. In fact, nearly three out of every four humans who get bitten by white sharks survive the encounter.

Biologists have proposed that when the animals bite people, they do so out of curiosity (at least, in most cases). “Great whites are curious and investigative animals. That’s what most people don’t understand,” marine biologist R. Aidan Martin told National Geographic. “When great whites bite something unfamiliar to them, whether a person or a crab pot, they’re looking for tactile evidence about what it is.”

The sharks often go out of their way to nibble on inanimate objects—such as underwater cameras—before losing interest and moving on. So maybe, when they decide to bite people, they're not looking for a snack.

11 Lesser-Known Animal Phobias

iStock.com/Scacciamosche
iStock.com/Scacciamosche

He’s dealt with elaborate booby traps, KGB agents, and a face-melting artifact, but to Indiana Jones, nothing’s more unsettling than snakes. Many people can relate. Ophidiophobia—or “the persistent and irrational fear of snakes”—affects roughly 1 to 5 percent of the global population. So does the clinical fear of spiders, also known as arachnophobia. But did you know that some people feel just as uncomfortable around chickens? From puppy-induced panic to equine terror, here are 11 lesser-known animal phobias.

1. Lepidopterophobia

Academy Award-winner Nicole Kidman is unfazed by spiders or snakes, but she can’t escape her lepidopterophobia, or fear of butterflies. As a young girl, the Australian actress once scaled a fence just so she could avoid a butterfly perched nearby. “I jump out of planes, I could be covered in cockroaches, I do all sorts of things,” Kidman once said, “but I just don’t like the feel of butterflies’ bodies.” (The Independent reported that she tried to break her phobia by spending time in a museum butterfly cage. “It didn’t work,” the actress said.) Kidman and her fellow lepidopterophobes may refuse to leave windows open in the summertime, lest a stray monarch come fluttering into their home.

2. Batrachophobia

A giant river toad
iStock.com/reptiles4all

No, frogs can’t give you warts. That urban legend—and others like it—may explain some cases of batrachophobia, a deep-seated fear of amphibians, including frogs, toads, and salamanders. It’s thought that the condition might also be linked to an overarching disdain for slimy things. By the way, if you specifically don’t like toads, then you could have a case of what’s known as bufonophobia.

3. Entomophobia

Entomophobia is a family of fears related to insects that includes lepidopterophobia, the previously mentioned butterfly-related dread. Another phobia within this group is isopterophobia, the fear of wood-eating insects like termites. Then we have myrmecophobia (the fear of ants) and apiphobia (the fear of bees or bee stings). Of course we can’t leave out katsaridaphobia, or the debilitating fear of cockroaches. “Cockroaches tap into this sort of evolutionary aversion we have to greasy, smelly, slimy things,” Jeff Lockwood, an author and professor of natural sciences at the University of Wyoming, told the BBC. “Plus, they’re defiant little bastards.”

Surrealist painter Salvador Dalí was terrified of grasshoppers. “I am 37 years old,” he wrote in 1941, “and the fright which grasshoppers cause me has not diminished since adolescence ... If possible, I would say it has become greater.” He went on to say that if a grasshopper ever landed on him while he was standing “on the edge of a precipice,” he’d instinctively jump to his death.

4. Ornithophobia

Traumatic childhood experiences involving birds—like, say, getting chased by a goose—can give birth to a lifelong fear of feathered critters. For Lucille Ball, they always reminded her of her father's untimely death when she was just a toddler: As her mother was delivering the horrible news, a couple of sparrows gathered by the kitchen windowsill.

“I’ve been superstitious about birds ever since,” Ball wrote in her autobiography. “I don’t have a thing about live birds, but pictures of birds get me. I won’t buy anything with a print of a bird, and I won’t stay in a hotel room with bird pictures or any bird wallpaper.”

5. Ailurophobia

Tabby cat against a gray background
iStock.com/Sergeeva

Lucy van Pelt (sort of) mentions ailurophobia in A Charlie Brown Christmas, although she bungles the nomenclature and tells Charlie Brown, "If you’re afraid of cats, you have ailurophasia." (The -phasia suffix generally refers to speech disorders, such as aphasia.) That being said, the fear of cats is a phenomenon that goes by many names, including gatophobia and felinophobia.

Rumor has it that Napoleon Bonaparte and lots of other famous conquerors were terrified of kitties. In Bonaparte’s case, the allegations are probably false; according to historian Katharine MacDonogh, “No record exists of Napoleon either liking or hating cats.” She thinks this myth reflects the long-standing cultural belief that our feline friends wield supernatural insights. “Cats have been endowed with a magical ability to detect the overweening ambitions of dictators, many of whom have consequently been accused of ailurophobia on the flimsiest evidence,” MacDonogh wrote in her book Reigning Cats And Dogs: A History of Pets At Court Since The Renaissance.

6. Alektorophobia

Chickens, hens, and roosters put alektorophobes on edge. A rare type of ornithophobia, this fowl-based fear is no laughing matter. One 2018 case study reported on a 32-year-old man who would experience heart palpitations, a sudden dryness of the mouth, and uncomfortable feelings in his chest upon seeing a neighbor’s hen. It was ultimately determined that the man's phobia was the result of a frightening childhood encounter he’d had with a rooster.

7. Ostraconophobia

“I have a lobster phobia, I don’t know why. I just don’t like them,” NASCAR driver Denny Hamlin told the press in 2017. “I cannot eat dinner if someone beside me is eating lobster.” The admission came just after Hamlin had won the Monster Energy NASCAR Cup Series. Why did that matter? Because the event took place at the New Hampshire Motor Speedway, where race-winners are customarily rewarded with giant, live lobsters. But when somebody approached Hamlin with a 44-pounder, he tried to flee the stage. Ostraconophobia, or fear of shellfish, can also manifest itself as a fear of crabs or oysters. The majority of people who deal with this phobia develop it after getting sick from the shellfish that makes them feel uneasy.

8. Ichthyophobia

Piranha fish on black background
iStock.com/bluepeter

Ichthyophobia is a bit of an umbrella term that covers an irrational disdain of fish in a variety of situations. It can refer to the fear of being around live fish, the fear of eating dead ones, or the fear of touching them. A common version of that first anxiety is galeophobia, the widespread fear of sharks. And then there are those who are disturbed (and sometimes even physically sickened) by the sight or smell of fishy entrees; these ichthyophobes may take pains to avoid supermarkets with large seafood aisles.

9. Musophobia

Among the British adults who participated in a 2017 phobia survey, more than 25 percent reported that they were afraid of mice. By comparison, only 24 percent said they dreaded sharp needles or airplanes. In addition to disliking mice, musophobes are often afraid of other rodents, such as hamsters and rats.

10. Equinophobia

Sigmund Freud once wrote a case study on a boy who was terrified of horses. At age 4, Herbert Graf—referred to as “Little Hans” in the paper—had seen an overloaded work horse crumble to the ground in a heap. Following the traumatic incident, Hans became easily spooked while in the presence of horses; just the sound of clopping hooves was enough to trigger his anxiety. As a result, Hans often refused to leave the house.

Little Hans eventually overcame his fears, but equinophobia is still with us today. Kansas City Chiefs safety Eric Berry developed it after being bitten by a pony at a petting zoo when he was a child. Unfortunately for Berry, one of the Chiefs’s mascots is a live pinto horse named Warpaint. As former teammate Derrick Johnson told NFL Films, “He’s always watching for the horse, making sure the horse doesn’t look at him or do something crazy.” Berry has taken steps to overcome his horse phobia, though; in fact, he has even worked up the courage to (briefly) pet Warpaint.

11. Cynophobia

Pug wrapped in a pink blanket
iStock.com/Alexandr Zhenzhirov

If you’re afraid of snakes, at least you’ll (probably) never have to worry about some coworker bringing his pet anaconda into the office. Cynophobes aren’t so lucky. Defined as the “fear of dogs,” cynophobia is an especially challenging animal phobia to have because, well, puppers are everywhere. Cynophobic people may go out of their way to avoid parks and tend to feel uncomfortable in neighborhoods where loud pooches reside.

As with ornithophobia, the fear of canines often stems from a traumatic childhood event. Therapists have found that, for many patients, the best way to overcome this aversion is through controlled exposure; spending quality time with a well-trained dog under a supervisor’s watchful eye can work wonders.

Survey: People Show More Affection to Their Dogs Than Their Humans

iStock.com/damircudic
iStock.com/damircudic

Valentine's Day is marketed as a celebration of love between two people, but for some human beings, the relationship they share with their dog takes precedent. Nearly half of pet owners have plans to celebrate the holiday with their pet, whether they're buying them a gift or making them a treat from scratch. That's one of the findings from a new report from Rover that shows just how much humans love their dogs—and how much dogs feel love from their humans.

After surveying 1450 U.S. adults who are dating or in a relationship, Rover found that many of them prioritize spending time with their canine companions. Sixty-seven percent reported gazing lovingly into their pet's eyes, and about 33 percent do this more often with their cute dog than with their human significant other.

The way our pets respond to this behavior suggests that dogs feel love, too. Phil Tedeschi, a University of Denver researcher and member of Rover’s Dog People Panel, says that dogs will wait for the opportunity to make eye contact with their humans. Previous research has shown that some dogs also express empathy when they think their owners are in distress.

When dog people aren't gazing at their pooches, they're finding other ways to show their affection. Nearly a quarter of dog owners take more pictures with their dog than with the humans in their life; a quarter spend more money on their dog than on their partner; and nearly half cuddle with their dog more often than they do with the person they're dating.

Pet parents also aren't afraid to cut people out of their life if they threaten their relationship with their dog. Forty-one percent say it's important that their dog gets along with their potential partners, and 53 percent would consider breaking up with someone who didn't like dogs or who was severely allergic to them.

You can check out the results of the report in the infographic below. And if you're looking for a last minute gift for Fido this Valentine's Day, here are some suggestions.

SECTIONS

arrow
LIVE SMARTER