Could a whale swallow a person whole?

In the upcoming movie Whalefall, scuba diver Jay Gardiner finds himself in the path of a sperm whale that is chasing a giant squid. Accidentally tangled in a stray squid tentacle, Gardiner is pulled into the whale’s mouth as it slurps up its meal. Like Jonah and Pinocchio before him, he winds up in the behemoth’s stomach.

It’s not completely beyond the realm of possibility for a sperm whale (Physeter macrocephalus) to accidentally swallow a person. A “very big adult sperm whale” could do it, says comparative anatomist Joy Reidenberg of the Icahn School of Medicine at Mount Sinai in New York City. But it would take a full-grown bull reaching lengths of 18 meters or more, “bigger than most of the ones that we’re used to seeing,” says Reidenberg, who worked as a consultant on the movie.

Other large whale species would struggle to do so. Take the fin whale (Balaenoptera physalus). Though capable of reaching lengths of up to 26 meters, fin whales have a surprisingly narrow gullet.

Reidenberg should know: Part of her job includes dissecting whale carcasses that have washed ashore. These are strained from seawater using sievelike plates of baleen, which creates a fishy slurry. For the whales, “it’s kind of like drinking a thick milkshake.” In a few rare instances, people accidentally get caught up by baleen whales going after prey; for instance, in 2019, a Bryde’s whale (B. brydei) briefly grabbed a wildlife photographer off the coast of South Africa before spitting him out.

But such cases aren’t intentional human hunting. Sperm whales, though, prey on some of Earth’s largest creatures. Their favorites include giant and colossal squid — the latter of which can reach 14 meters long (with tentacles) and weigh hundreds of kilograms.

Based on how sperm whales’ smaller cousins, like belugas, feed in captivity, researchers think the behemoths suction up prey by depressing a bone in their throat called the hyoid. As the hyoid lowers, their tongue draws back. This works like a piston, creating an area of low pressure to draw water — and unsuspecting prey — into the whale’s mouth and widening its throat and the opening to the esophagus.