Rorqual whales have stretchy nerves for taking big gulps

Some of the world's largest vertebrates — rorqual whales — have a unique feeding strategy that is, researchers have discovered, facilitated by stretchy nerves, something that perhaps isn't surprising given how widely these whales open their jaws to eat. It has long been known that these whales take big gulps when feeding, and according to a new study published in Cell, those giant mouthfuls are possible, in part, due to elastic nerves that are not common in vertebrates. The discovery was accidental.

Rorqual whales include the massive humpback and blue whales, which are known to feed by opening their jaw's widely and consuming a large quantity of both food and water, so much so that the skin around their jaw may bulge. According to the Canadian researchers who made the discovery, the nerves are stretchy like bungie cords.

Researcher and zoologist Robert Shadwick is the one who discovered they're stretchy; he is said to have grabbed one of several long white cords near muscles in the floor of a whale specimen's mouth. Says the study's first author Professor Wayne Vogl, "Bob picked one up – about 3ft. of it — grabbed each end and stretched it."

That cord, which was first thought to be a blood vessel, was able to stretch double its length and spring back to its original size. The white part of the nerves is elastin, while the nerve fibers themselves were said to be wound inside of a core, allowing them to unfold as the outer portion of the nerve stretches.