Bungee Nerves Key to Whale-Sized Gulps, New Research Shows
Giant whales may have stretchy nerves that allow them to gulp water more in volume than their bodies, researchers have found.
The astounding discovery was made by researchers from University of British Columbia (UBC) who were studying whale specimens in Iceland. The researchers were studying the jaw of a fin whale when noticed a cord that stretched. Assuming it was a blood vessel, they cut it open expecting to find a hollow cavity. Instead they learnt it was a nerve.
"This discovery was totally unexpected and unlike other nerve structures we've seen in vertebrates, which are of a more fixed length," said Wayne Vogl of UBC's Cellular and Physiological Sciences department.
Given the mechanism of jaw operation of large whales like the Blue Whale, researchers hypothesize that a stretchy nerve could be the key. The whales have to open their jaws wide enough to gulp in large volumes of water, expelled after collecting prey.
"The rorquals' bulk feeding mechanism required major changes in anatomy of the tongue and mouth blubber to allow large deformation, and now we recognize that it also required major modifications in the nerves in these tissues so they could also withstand the deformation," Vogl informed.
Microscope study of the nerve showed that the nerve fibers could unfold as the cord itself stretches. A rope like structure made of collagen fibers keeps the nerve from stretching too far while the outer layer is made of elastic, a fibrous protein found in human skin and blood vessel, reports BBC.
The discovery has fuelled interest to study the jaw workings of large whales in greater detail.
"Our next step is to get a better understanding of how the nerve core is folded to allow its rapid unpacking and re-packing during the feeding process," said zoologist Robert Shadwick.
