Blue and humpback whales have stretchy nerves in their jaws which help them swallow large volumes of water and food, sometimes even bigger than themselves, according to a recent study.
Researchers made the discovery when they accidentally pulled a long, thick cable they found in the jaw of a fin whale. Subsequently, they found most nerves to be fragile and inelastic, which makes this find a first for vertebrates, according to the BBC.
The study, which was published in the journal Current Biology, revealed that the floor of the oral cavity expands by inversion of the tongue and ballooning of the adjacent floor of the mouth into the cavume ventral– an immense layered pocket or throat area. The ventral grooved blubber in fin whales expands by a whopping 162 percent in circumferential direction and 38 percent longitudinally.
In most vertebrates, nerves are surrounded by a thin collagen wall, and overstretching can cause irreparable damage. The nerves in the mouths of fin whales are highly folded at rest, but when the whale opens its mouth and proceeds to feed by gulping water, the nerve stretches to its full, straightened length. Thick elastin wall surrounding the nerve helps them recoil back to resting state, according to The Guardian.
[quote text_size=”small” author=”– Wayne Vogl” author_title=”Anatomist at the University of British Columbia and the study’s first author”]
We were looking at the muscle in the floor of the mouth and there were these long white cords. (…) We thought it was a blood vessel. Later, I realized this was a nerve, and it was very different from any other nerve I’ve ever seen.
“Having functioning nerves is crucial to the whale’s survival,” says Dr. Guy Berwick, a neuroscientist at the University of Aberdeen in Scotland. “After taking a gulp, whales filter it through their baleen plates, keeping the fish and krill, but letting go of the water. To squeeze the water out again, whale needs to contract huge muscles in the floor of the mouth, and muscles won’t contract unless nerves tell them to,” concludes Dr. Berwick.
Unrelated to this study, female killer whales become leaders after menopause, improving the chance of survival for the group, according to a group of scientists.