WASHINGTON, May 24 (UPI) -- U.S. and Canadian scientists say they've discovered a sensory organ in rorquals that helps the whale species with its "big gulp" feeding technique.
Rorquals are a subgroup of baleen whales that have an expandable, accordion-like blubber layer from the snout to the navel that can open to allow them to take in huge amounts of water and then filter out krill and fish.
Some rorquals can engulf as much as 2,800 cubic feet of water and prey, a greater volume than that of the whale itself, in each gulp of less than 6 seconds, researchers said.
Scientists at the University of British Columbia and the Smithsonian Institution studying rorqual carcasses discovered a grapefruit-sized sensory organ at the tip of the whale's chin in tissue that connects its two jaws, TG Daily reported Thursday.
"We think this sensory organ sends information to the brain in order to coordinate the complex mechanism of lunge-feeding, which involves rotating the jaws, inverting the tongue and expanding the throat pleats and blubber layer," Smithsonian paleobiologists Nick Pyenson said.
The sensory organs in the whale carcasses were examined using X-ray tomography.
"In terms of evolution, the innovation of this sensory organ has a fundamental role in one of the most extreme feeding methods of aquatic creatures," University of British Columbia zoology professor Bob Shadwick said.