The great white shark both frightens and fascinates. With its large jaws packed with around 300 razor-sharp teeth, it’s one of the world’s most formidable predators.
It’s by no means the largest shark in the world, that title goes to the plankton-munching whale shark, but it is the largest predatory fish and, as such, has very few natural predators.
Although great whites are responsible for more shark attacks on humans than any other species, you’ve still got more chance of being struck by lightning than bitten by a great white.
However, I still wouldn’t advise jumping into the water with a 15-foot great white. Even an exploratory bite from a great white can be fatal.
We know that great white sharks are bigger than most other shark species, but just how big are they, and what are the chances of them getting even bigger as their evolution continues?
How Big do Great White Sharks Get?
At birth, great white sharks already measure between approximately 3.9 and 5 feet long. During the first 10 to 15 years of their lives, these juvenile white sharks grow at a rate of 9.84 inches per year.
By the time male great white sharks reach sexual maturity at around 10 years old, they measure 11.5 to 13 feet in length.
Females take a little longer but grow much bigger, reaching sexual maturity between 12 and 18 years old, by which time they’re approximately 15 to 16 feet long.
In most large marine fish species, the females are bigger than the males “because they need more girth to carry their young.”
Given that a female great white can carry up to 12 pups, each one measuring between 4 and 5 feet long, it’s hardly surprising she can reach lengths of up to 20 feet!
For many years, it was believed that great white sharks could reach phenomenal sizes, exceeding 36 feet and over 7,000 lbs. A shark caught at Port Fairy in Australia in 1870 “had a reported length of 36.5ft.”
When Dr. John Randall measured the teeth of this massive shark in 1973, he estimated that it was closer to 16.5ft than 36.5ft.
The same thing happened to another great white caught in 1930. Initially believed to be around 37ft, the specimen’s tooth size indicated that it was more like 17ft!
Compared to a 37-foot shark, a 17-footer sounds quite small, but if you were to find yourself swimming next to one, it would seem huge.
I’m around five feet tall, so a 17-foot shark is nearly three and a half times bigger than me, and that’s only the length!
A 17-foot great white would be nearly 7-foot tall so even if I was swimming vertically, it would still tower over me.
Not only that, but its jaws would be around 3 feet wide, meaning the shark could almost swallow me whole if it was so inclined.
Fortunately, humans are not the white shark’s preferred prey, and even the biggest great white shark would opt for seals over humans.
Although they don’t like human flesh, they’re not exactly picky eaters. In addition to marine mammals and fish, sharks will also feed on whale carcasses, even if they’ve started decomposing!
What is the Biggest Great White Shark ever Recorded?
In May 2011, the Shark Men expedition crew caught and released a 17.9-foot-long shark off the coast of Guadalupe Island.
It was over a foot longer than the team’s previous record – a female shark that measured 16.8 feet. As impressive as these specimens are, they can’t compete with the largest shark specimen ever recorded.
In 1983, a Canadian fisherman called David McKendrick accidentally caught a great white shark when it became entangled in his fishing net off Prince Edward Island.
It took three hours for McKendrick and his crew to land the shark which turned out to be a 20-foot great white.
This remains possibly the largest specimen ever caught and its length has been verified by the Canadian Shark Research Laboratory.
The development of radiocarbon dating enabled researchers to age the specimen over 10 years after it was caught.
By “looking for evidence of exposure to radioactive fallout from nuclear weapons testing in the 1950s and 60s,” researchers were able to establish that the 20-foot shark was just 20 years old when it died – a mere teenager by shark standards.
According to Steven Campana, head of the Canadian Shark Research Lab at the Bedford Institute of Oceanography in Nova Scotia, “If it would have lived longer it would have gotten a lot bigger…. It was a big shark, but it still had a lot of growing to do.”
When great white sharks reach sexual maturity, their growth rate slows but never stops. Even if this giant shark was growing at just half the rate of a juvenile, she could have doubled in size by the time she reached 70 years old.
Even if she’d died at 40, she still would have been over 28 feet long!
That’s even bigger than Deep Blue, the largest great white ever caught on camera. Deep Blue is a female shark estimated to be around 20 feet long.
She was initially identified in the 1990s, but footage of her only emerged in 2013, when Mauricio Hoyos Padilla, a marine biologist, and shark movement specialist, captured Deep Blue swimming on camera.
Marine biologists estimate that Deep Blue is approximately 20 feet long, eight feet high, and weighs around 2.5 tons, although these figures have never been scientifically proven. She was also heavily pregnant in 2013, which would have added to her overall size.
According to some, without scientifically measuring Deep Blue, there’s no way of knowing if she’s the largest fish in the sea or not.
Michael Domeier, the president and executive director of the Marine Conservation Science Institute, claims he’s seen “seen two massive sharks that could definitely exceed Deep Blue in size.”
Domeier may have a point. Way back in 1945, fishermen off the coast of Cuba hauled in a huge shark using only harpoons and ropes. The creature they landed proved to be a 21-foot-long, 7,000 lb great white shark.
While that may sound like yet another tall story, a few years ago, a Discovery Channel documentary crew confirmed the tale, making “El Monstruo de Cojimar” the largest great white shark ever seen.
Do 35-foot Great White Sharks Exist?
Others make similar claims, but finding proof is difficult. According to the spear fishermen that posted this video, the specimen they saw swimming under their fishing boat was around 30 to 35 feet long, but there’s no evidence to prove it.
They’re not the only ones to believe a 35-foot great white could be patrolling our waters, however.
Filmmaker and shark expert Dave Riggs tagged a nine-foot great white shark off the coast of Western Australia, only for the creature to be eaten alive a few months later. This incident inspired him to search for further evidence, which he found.
Curt Jenner, director of the Centre for Whale Research in Australia, confirmed the possible existence of a large great white by analyzing an old shark bite scar on a pygmy blue whale.
According to Jenner, was the largest bite he’d ever seen, and he has little doubt a shark was behind it.
By estimating the size of the bite marks, Riggs and Jenner believe the shark responsible for it could be between 35 and 39 feet long.
Unfortunately, Riggs’ attempts to get a closer look at the shark failed, and, for now, his theories are still in the category of myth rather than reality.
Why do Great White Sharks get so Big?
Great white sharks never stop growing and can live for around 70 years, so it stands to reason they can get pretty big, especially as they start life already measuring 5 feet in length.
The largest species of mackerel sharks, the great white is endothermic, so uses energy to generate body heat, as well as energy and body mass.
Neil Hammerschlag, research assistant professor at the University of Miami’s Rosenstiel School and Abess Center, believes there are several factors that influence a shark’s growth.
Some individuals may be “naturally predisposed to be larger,” but “environment and food supply are also important.”
He believes great whites living in warmer waters may get bigger than those in cold waters due to the availability of nutritious meals, like whale blubber.
To sustain their high level of activity, great whites need to eat around 2.5 kgs of meat and blubber per day. If they’re to continue growing, they need even more.
Will They get Bigger or Smaller in the Future?
Scientists believe both great whites and tiger sharks are getting bigger, and it’s largely thanks to us that it’s happening.
National Geographic was so curious about these reports, that they investigated themselves, creating the documentary, Great White vs. Tiger Shark.
Their research indicates that the giant sharks are “gorging themselves on fish in protected waters,” causing them to become bigger and fatter than ever before.
Some of these so-called “megasharks” are reaching lengths of 20 feet, and are working together to ensure they get the nutrition they need to grow even bigger.
Researchers have also “observed female great white sharks working together to hunt and eat prey, including whales,” which could explain why they’re thriving.
If warmer waters also mean bigger sharks, then the fact “the average global sea surface temperature has increased about 1.5 ℉ since 1901,” also goes some way to explaining the rise of the megashark.
How About the Past?
In the “golden age of sharks,” some 350 million years ago, hundreds of different shark species explored our oceans.
Some of them had strange physical adaptations, like the Helicoprion with its buzz saw-like bottom jaw, while others simply grew to incredible proportions.
Unfortunately, a mass extinction event occurred at the end of the Cretaceous period (145 to 66 million years ago), killing off “many of the largest species of shark.”
Large predators with eating habits similar to those of the great white disappeared, leaving only “the smallest and deep-water species” behind.
It didn’t take long for the shark to bounce back, however. By the time the Palaeogene era came around some 66 to 23 million years ago, the megalodon’s ancestor, Otodus obliquus, had arrived, as had the great white.
Just how big those great whites were is unclear, but they proved to be such efficient hunters that they potentially contributed to the megalodon’s extinction.
It may also have been the megalodon’s sheer size that made it unsustainable. Measuring around 50 feet long, it would have had an insatiable appetite.
Any competition for food would have had a huge impact on it, leaving the largest great white sharks to fill their niche.
Most great white sharks grow to between 11 and 16 feet long, but there are an increasing number of larger sharks inhabiting our oceans.
To date, Deep Blue is the largest great white shark in existence. The only sharks to come close to her are long dead, but there could be others out there that make even Deep Blue seem small.
The possibility of 30 to 35-foot monsters trawling in deeper water continues to fascinate shark enthusiasts and researchers alike.
As the ocean temperature rises and protected fishing zones provide plentiful food, there’s every chance we’ll see even larger sharks in the future.
No matter how big great white sharks get, however, they’ll still remain relatively harmless.
Fortunately for sea lovers all over the world, great white sharks prefer seals to human flesh, which makes shark attacks extremely rare.
Better still, larger sharks are liable to prefer deeper waters, making the chances of a close encounter even less likely.
Nicky is a British adventurer and animal lover who spends her time exploring the natural world and writing about her experiences. Whether on horseback, underwater, running, hiking or just standing with a fishing rod in hand, she embraces everything her adopted home of South Africa has to offer.