Have you ever wondered whether whales can burp and why they don’t die after consuming gallons of water and krill?
A New UBC study might hold the key.
Researchers discovered that lunge-feeding whales have an ‘oral plug,’ a fleshy bulb in their mouths that slides backward during eating to shut off the top airways while their larynx closes to block the lower airways.
According to a report published today in Current Biology, this block prevents water from entering their lungs as they eat.
But There’s More
Lunge-feeding whales consume by lunging towards their prey, accelerating quickly, then opening their mouths to swallow water and krill.
According to Dr. Kelsey Gil, a postdoctoral researcher in the zoology department, this number may sometimes be more significant than their bodies, which is an astounding achievement considering that this group includes the humpback and blue whales, the two most giant animals on the planet.
Water is subsequently drained through their baleen, a filter-feeding system inside the mouths, leaving behind the tiny, delicious krill to be consumed.
The researchers studied fin whales, a species of lunge-feeding whales, and discovered that the ‘oral plug’ required to shift for food to get to the esophagus.
It could only go to the back of the whale’s head and up, closing up the nasal passages when the whale swallowed.
Dr. Gil explains that at the same time, cartilage shuts at the entrance to the larynx and the laryngeal sac travels higher to cut off the lower airways. He added that this defensive mechanism had not been seen in other species or literature.
Because we know so much about whales and dolphins from toothed whales, which have entirely different respiratory systems, similar assumptions have been made for lunge-feeding whales.
We Share Some Anatomy
Humans, it turns out, we have a similar mechanism for swallowing food without the risk of getting anything in our lungs: we have the epiglottis and soft palate, which are a cartilage ‘lid’ and a muscular flap in our throat and mouth, respectively.
According to Dr. Gil, humans could certainly eat underwater as well, but it would be like swimming at great speed towards a cheeseburger and opening your mouth wide as you approached—it would be tough not to fill your lungs.
According to the experts, whales’ oral plug and closed larynx are essential to how lunge-feeding originated and is vital in these species’ immense size. He added bulk filter-feeding on krill swarms is very efficient because it is the only method to give the vast quantity of energy required to sustain such a gigantic body size.
Dr. Robert Shadwick, a professor of zoology at UBC, is the senior author who thinks this would not be feasible without the unique anatomical traits we’ve discussed.
Investigating whale anatomy sometimes involves dissecting whales that have died due to stranding, which presents problems such as completing work before the sea rises.
On the other hand, Dr. Gil and her colleagues dissected whales in Iceland in 2018, retrieving tissue that wasn’t utilized for food from a commercial whaling site.
She thinks working with whales in real-time would be fantastic. Still, it may need some technological advances, adding that it would be intriguing to put a tiny camera into a whale’s throat while it was eating to watch what was going on. Still, researchers would have to make sure it was safe to eat and biodegradable first.
The researchers will continue to investigate the mechanics of the pharynx and the narrow esophagus, which are responsible for swiftly moving hundreds of kilos of krill to the stomach in less than a minute.
With so many human influences disrupting food chains, understanding how whales feed and how much they consume, it’s essential to learn as much as possible about these creatures to safeguard them and their ecosystems, adds Dr. Gil.
There’s also the question of whether whales cough, hiccup, or, yes, burp. Dr. Gil. thinks humpback whales blow bubbles out of their mouths, but experts don’t know where the air comes from—it may make better sense and be more effortless for whales to burp out of their blowholes.
