Can A Blue Whale Sneeze Out A Fish?
In the movie “Finding Nemo”, two characters (Marlin and Dory) allow themselves to get sucked into a blue whale’s mouth in order to hitch a ride with the whale. Once they reach their destination, the whale swallows them and then shoots them out through its blowhole. A number of sites online point out that this scenario is impossible, since a whale’s respiratory and digestive tracts are not connected, as they are in humans.
When I read this, I thought, “Wow — that’s crazy… I wonder what that looks like in real life. And how did they evolve such a different throat architecture?”
It turns out evolution is pretty clever, making use of the same basic parts all mammals have, but stretching and bending them (literally) to the needs of the animal. This also means, though, that the separation between a whale’s respiratory and digestive tracts isn’t as absolute as most of the articles online imply, and it might actually be possible for Nemo and Dory to get out of that whale’s mouth through its blowhole.
But let’s start with the basics. The nasal passage and mouth of humans (as you’re probably aware) are connected, which is why if you sneeze while swallowing a mouthful of food, some of it might come out of your nose. Your throat branches off a little farther down: your larynx and trachea bring air to your lungs, while your esophagus brings food to your stomach. A fibrous piece of muscle and cartilage called the epiglottis at the opening of the larynx steers food away from the trachea, preventing food from getting into your lungs.
Whales, meanwhile have one pathway just for air: the respiratory tract, which starts with the blowhole(s) (toothed whales like dolphins and killer whales have one, while baleen whales generally have two) and leads down to the nasal passage. An elongated tubular larynx (sometimes referred to as a “goose-beak” in toothed whales because of its shape) connects the nasal passage to the trachea (wind pipe), which then brings air to the lungs. Food, meanwhile, follows a completely different path, entering from the mouth, then to the pharynx, the esophagus, and finally the stomach.
The benefit of this arrangement is pretty straightforward— as long as they keep their blowhole(s) closed, whales would never accidentally get water or food into their lungs, which, as you might imagine, is a pretty big risk when you spend all your life under water and everything you eat comes with a big slug of water.
It turns out many other animals — most notably horses, cows, and other ruminants — also have this adaptation. It allows them to eat while keeping their noses open for predators. (But if this arrangement is so great, why don’t all animals have it? Well, our setup has its own benefits — during high-intensity activities, it allows us to get extra air through our mouths.)
While a whale’s digestive and respiratory tracts are separate, they aren’t completely isolated from each other. The larynx actually passes through the pharynx in order to get from trachea to the nasal passage. If you were a fish being swallowed by a whale, the larynx would look like a huge fleshy pipe running from the floor to the ceiling of the whale’s throat, and you’d have to pass to either side of it to get to the esophagus. The “top” end of the larynx would be connected to the nasal passage, while the “bottom” end leads to the trachea.
Furthermore, the larynx isn’t permanently fused to the nasal passage — instead, it is inserted into nasal passage the way a hose might be inserted into vacuum cleaner, and is held in place by a muscle called the palatopharyngeal sphincter. In baleen whales (such as the blue whale in “Finding Nemo”), this connection or “interlock” is somewhat flexible, and there’s some evidence that whales can disconnect their larynx from the nasal passage voluntarily.
For example, humpback whales have been regularly observed blowing bubbles out of their mouths in order to herd fish together. This would only be possible if the whale detached its larynx in order to channel air from its lungs to its mouth. (Kind of a reverse Marlin & Dory situation.)
Even in the case of toothed whales, there is some debate over how strong the connection is or how movable the goose-beak is. In an e-mail exchange, Joy Reidenberg, a professor of anatomy at Icahn School of Medicine at Mount Sinai, described the goose-beak as “permanently intranarial,” and notes that, “I have only seen it dislodged in extreme circumstances (severe gag reflex) that resulted in death.”
However, Alex Costidis of Virginia Aquarium and Marine Science Center is not entirely convinced, and wrote to me that “Morphologically speaking, the palatopharyngeal sphincter… can be quite loose (when not contracted) and the goose-beak can easily be slipped out. This is seen rather commonly with dolphins that try to swallow a fish that is too large. Of course we only get to see the cases that don’t survive that risky maneuver, but I suspect it happens more times than we know about.”
There is even one well-documented instance of a dolphin that was also able to learn to breathe through its mouth, possibly due to some blowhole defect or damage.
Dr. Costidis also noted that “Veterinarians use this biomechanical plasticity to intubate odontocetes [toothed whales like dolphins and killer whales] for anesthesia.” A person can reach into a dolphin’s throat and “dislocate” the larynx. “The airway can then be tubed and connected to an anesthesia machine.”
So back to Marlin, Dory, and their predicament. Could the whale have swallowed Marlin and Dory part-way, then expelled them through its blowhole? Dr. Reidenberg told me, “It would be very unlikely as the suction to swallow is very strong”, so if the whale starts to swallow, Marlin and Dory would most likely end up in its stomach. However, she wrote, “I could imaging something climbing around the interlock and forcing itself into the nasal passageway where it could be launched like a loaded cannonball from a cannon!”
So Marlin and Dory would have some work to do, but nothing a couple of plucky fish can’t handle. A few years back, a couple of pilot whales washed up on shore with fish stuck in their blowholes, and some surmise that’s what happened to them — the fish wriggled their way around the interlock into the whale’s nasal passage. Unfortunately for both the whales and the fish, the fish never managed to make their way out of the whales’ nasal passage, but if the fish were small enough and the whale was big enough, it might’ve worked out in the end.
At the end of the day, though, we’re still only speculating, since, as Dr. Costidis noted to me, “It’s next to impossible to peer down the mouth of a live large whale, though technology may eventually allows us to do so.”
Many thanks to Professor Joy Reidenberg and Dr. Alexander Costidis for sharing their knowledge and thoughts on this topic, as well as their feedback on this article.
