Smithsonian.com

Image: Adinda Navartierre

Whale sharks are really big. Their mouths can get up to five feet long, and they can suck in 600 cubic meters of water every hour. Swimming next to one, then, might take you back to Pinocchio’s trip into the whale’s belly. And suddenly you might worry that that could actually happen to you. Could a whale shark swallow you by accident?

The quick answer is no. Dr. Craig McClain explains:

I know that the esophagus of a whale shark measures only inches across. The massive beast could not choke me down even if it preferred man meat to plankton.

The sharks know that they can’t eat you, and they often close their mouths around big prey like you or big fish. But if they did accidentally take you into their mouths, what would happen? Real Clear Science asked Phillip Motta, a researcher at the University of South Florida:

“My educated estimate is that the shark would immediately spit out the person,” Motta said.

In 2010, Motta led a study that focused on whale sharks’ feeding anatomy and behavior. One thing he and his team found was that the animals really don’t like eating anything that’s foreign to their diet.

“We actually threw seawater soaked rice in front of whale sharks to time the flow of water into the mouth as they filter fed on the surface. They would spit out the one handful of rice as soon as it entered the mouth. We also threw Sargasso seaweed in front of them and they spit that out also.”

Okay, so whale sharks won’t swallow you. But what about toothed whales? They do sometimes swallow prey whole, so you could fit down their esophagus. Sperm whales sometimes swallow squid whole, so it could definitely manage a human. In fact, there’s a story of a sailor being swallowed by a sperm whale off the Falkland Islands in the early 1900s. The story says that aftter sailors chased a sperm whale for several hours, the whale caused a few men to be pitched in to the ocean. Then, well, this happened:

The whale was dead, and in a few hours the great body was lying by the ship’s side, and the men ere busy with axes and spades cutting through the flesh to secure the fat. They worked all day and part of the night. They resumed operations the next forenoon, and were soon down to the stomach, which was to be hoisted to the deck. The workmen were startled while labouring to clear it and to fasten the chain about it to discover something doubled up in it that gave spasmodic signs of life. The vast pouch was hoisted to the deck and cut open, and inside was found the missing sailor, doubled up and unconscious. He was laid out on the deck and treated to a bath of sea-water, which soon revived him, but his mind was not clear, and he was placed in the captain’s quarters, where he remained to [sic] weeks a raving lunatic. He was carefully treated by the captain and officers of the ship, and he finally began to get possession of his senses. At the end of the third week he had finally recovered from the shock, and resumed his duties.

In reality, this is unlikely. Sperm whales have four stomach chambers, like a cow, full of digestive enzymes. Plus, there’s no air inside a stomach. The Naked Scientist addressed this question as well, saying:

If there is any gas inside a whale, it’s probably methane, and that’s not going to help you out very much.  We do know that whales can be flatulent, so there is some gas.  They do have gassy pockets, but it’s not air, not good to breath.  Certainly, no air inside a fish, so I think that’s really what’s going to get you in the end.  So I’m afraid no.

So if the moral here is, whale sharks can’t and won’t swallow you. Sperm whales might, and if they do, you’re basically doomed.

More from Smithsonian.com:

The Tail of the Whale
Swim With The Whales