Fin whales are able to eat without choking thanks to a particular anatomical structure of the palate, a sort of fleshy 'plug', which closes and protects the respiratory tract, preventing water and krill from ending up in the lungs.
The discovery is published in the journal Current Biology by researchers from the University of British Columbia (Canada).
By dissecting some deceased specimens in Iceland, experts have identified this sort of fleshy bulb that blocks the canal between the mouth and pharynx.
When the animal eats, the cork moves to the back of the mouth blocking the passage to the nose.
At the same time, a cartilage layer blocks the entrance to the larynx, which in turn moves upward to close the lower airways.
The system is somewhat reminiscent of what allows humans to eat without choking: "it is like when the pendulous veil moves back to close the passage to the nose and our trachea closes during swallowing," explains the zoologist Kelsey Gil.
"We have never seen a similar mechanism in other animals or in the literature:
The researchers now intend to continue their studies, not only to learn more about the mechanisms that allow fin whales to feed, but also to discover other curiosities, such as whether fin whales can cough, burp or have hiccups.