After leaping into the sea, allowing himself to sink to the very bottom, a scuba diver came face to face with a huge tiger shark, the predator going into “hunt mode” as it picked up the scent of its unexpected visitor.
In the now-viral footage posted to TikTok, the diver, who goes by the name Scuba Dan online, films as a tiger shark swims nearby. The shark’s eyes then abruptly change from solid black to pure white as the animal catches the smell of the diver nearby.
As Dan Senior (aka Scuba Dan) explained, the shark’s off-putting color-changing eyes aren’t actually changing color at all. Instead, the shark is covering its eyes with a membrane meant to protect its most delicate feature.
“The white eyes are a protective membrane,” diver Dan Senior told Newsweek. “So when a shark is about to eat or in ‘hunt mode,’ the layer of white will come up to protect its eyes from getting scratched by prey trying to get away.”
@scubadan_ Sharks are super-sensitive to smells that are important to their survival 😱 Including scents produced by potential predators, prey or a mate 😧 So maybe she was trying to flirt! #sharks #sharkbait #tigershark #greatwhiteshark #tigersharks #sharktok #screammovie ♬ Creepy and simple horror background music(1070744) – howlingindicator
As the shark swims closer to the diver, she realizes he wasn’t her dinner of choice, uncovering her eyes as she passes. At the last moment, however, the membrane flicks down once again, indicating she might be having second thoughts.
This protective covering, called a nictitating membrane, extends from the lower eyelid. And though they’re slightly terrifying on a shark, they’re actually quite common in the animal kingdom. Known as a “third eyelid,” fully developed nictitating membranes can be found in fish, amphibians, reptiles, birds, and mammals. Even dogs and cats have them!
Not all sharks possess the protective covering, however. The great white shark, for example, rolls its eyes backward to protect itself from potential damage instead.
Shark Species Spotted by Diver Among the Most Dangerous in the Sea
Tiger sharks, such as the one briefly interested in the diver, inhabit the world’s temperate and tropical waters. Among the largest species of shark in the ocean, tiger sharks commonly reach 10-14 feet in length. The largest on record stretched a staggering 24 feet in length – longer than the largest great white.
Next to the great white, tiger sharks are responsible for more unprovoked attacks on humans than any other shark species. That said, tiger shark attacks remain extremely rare. You’re almost 400 times more likely to fall victim to a dog attack than find yourself in a shark’s jaws.
As the National Oceanic and Atmospheric Administration explained, the vast majority of shark attacks are cases of mistaken identity. The shark sees splashing in the water and assumes it’s a seal or large fish, not a human swimmer, surfer, or diver. Confused, the shark bites down on an arm or leg only to realize the taste is all wrong and retreat.
Diver Dan Senior agrees wholeheartedly, adding that in his 11 years of diving with sharks, his scariest encounter by far was with a blue-ringed octopus. Just 4-6 centimeters in length, the tiny blue-ringed octopus is deceptively dangerous. With venom 1,000 times more powerful than cyanide, the colorful cephalopod is capable of killing 26 humans within minutes.
“All sharks must be respected,” the diver clarified. “They are not the man killers that [the] Jaws movie makes out, but they are sharks and they are built to survive in any way they can.”