Arctic seals ’ intricate nose bones keep them warm in forever winters

To survive winter’s frigid embrace, many of us rely on heating units. But for seals facing life in perpetual winters, it helps to have one built in. In a study published today in the Biophysical Journal , researchers show that the unique nose bones in arctic seals preserve more warmth than the noses of their cousins in warmer climates. When arctic seals huff and puff, icy air and water molecules fly up their nares and into a labyrinth of nose bones called maxilloturbinates. These porous bones are lined with mucus-rich tissues that trap heat and soak up water when the animals breathe. To test the air-warming abilities of seal noses, researchers made 3D models of the maxilloturbinate mazes from CT scans (pictured) of bearded seals ( Erignathus barbatus ), native to Arctic regions, and subtropical Mediterranean monk seals ( Monachus monachus ). Then, they simulated seal breaths in cold (–30°C) and mild (10°C) conditions. The simulations showed that arctic seal noses retained significantly more heat and moisture in both environments. Arctic seals shed 23% less energy per breath than the subtropical seals, allowing them to retain more heat. They also retain 94% of the water they breathe. Seals, like many marine mammals, get most of their water from food. By retaining moisture in their bodies, they stay better hydrated. This natural humidifying system arises from the increased perimeter of the nose bones in arcti...
Source: Science of Aging Knowledge Environment - Category: Geriatrics Source Type: research