Revisiting convergence: whale epiglottis-like organ (Introduction)

by David Turell , Thursday, January 20, 2022, 18:38 (1037 days ago) @ David Turell

Whales that gulp huge amounts of sea water block lungs from water:

https://www.sciencenews.org/article/fin-whale-eat-choke-baleen-oral-plug-muscle-fat

"Some of the world’s largest whales feed by lunging through the water with mouths wide open. Scientists have long wondered how the animals withstand the tremendous pressure of water rushing into their throats without choking and drowning.

"A plug made of muscle and fat found at the back of fin whales’ mouths might offer a clue. The plug blocks the channel between a fin whale’s mouth and its pharynx, the entrance to the respiratory and digestive tracts. The plug appears to prevent water from rushing into the whale’s lungs and stomach while it lunges and could explain how all lunge-feeding whale eat without choking, researchers report January 20 in Current Biology.

“'Think of [the plug] as a trapdoor,” says Kelsey Gil, a marine biologist at the University of British Columbia in Vancouver. “It’s always closed unless muscular activity pulls it out of the way.”

***

"When a whale gulps water, the pressure leads to the plug creating a tight seal over the whale’s pharynx. Then, with a mouth full of water and prey, a fin whale pushes the water out through its baleen plates before it swallows. The swallow reflex probably activates the muscle that pulls the plug up to the top of its throat, blocking the upper airways and letting prey slide into its digestive tract. The plug, which appears to be unique among mammals, may explain how other lunge-feeders eat without choking on water, the scientists say.

“'The discovery of the ‘oral plug’ answers a long-standing question about how whales can simultaneously protect their respiratory tract while opening their mouths wide to engulf prey-laden water,” says Sarah Fortune, an expert in large whales at Dalhousie University in Halifax, Nova Scotia,..."

Comment: An obvious arrangement designed when these whales first appeared in evolution. They could not plunge/gulp feed without it. Imagine trying to gulp feed without it.