Big baleen whales have stretchy nerves helping them to gulp volumes larger than themselves?

The way baleen whales feed is very interesting indeed. They suck in huge quantities of water at a time and then filter its prey with the help of its comb-like teeth known as baleen. In has been observed in some species of whales that the volume of water swallowed in a lunge can very well be greater than the volume that the whale occupies.

For the whales to attain this kind of physical distortion, they need stretchy nerves as experimented by researchers who took fin whale nerves obtained from carcasses at a commercial whaling station in Iceland and stretched the. The researchers stated in Current Biology “Large nerves that supply the tongue and ventral grooved blubber in fin whales are like bungee cords. The nerves…can more than double their length without hindering their return to resting length after extension.”

This is a little strange as most vertebrates, nerves are surrounded by a thin collagen wall and overstretching it has the possibility of causing irreparable damage. However, in the mouths of fin whales, the nerves are highly folded at rest and when the baleen whale opens its mouth, the nerve unfold to their full, straightened length with a thick surrounding wall of elastic for assisting it to recoil it back to its state of rest.

Prof Wayne Vogl, an anatomist at the University of British Columbia and the lead author of the study explains, “They’ve used building blocks that are present in other animals but they’ve used them in different ways to produce this stretchy nerve.”

Dr Guy Berwick, a neuroscientist at the University of Aberdeen in Scotland, said he was surprised and really impressed by the finding and said, “I’ve studied nerves and muscles my entire career, and one of the things that you really try and avoid, in the clinical situation or just personally, is stretching your nerves.”

“Nerves are generally really quite fragile things; they’re quite well protected and they don’t withstand stretch well at all. This looks like a really neat trick to get around that problem, which the whale obviously needs to do because its mouth inflates so much.” Having functioning nerves is critical for the survival of the whale, added Dr Berwick.

In fact, evolutionary biologists have suggested that lunge feeding is the development which has allowed whales to reach their massive sizes, therefore, stretchy nerves is possibly one of the key adaptations which produced these mammoths of the unfathomable.