Natural Coolant

摘要

This infrared image of a sea star from California's Bodega Bay reveals how it keeps cooler than its surroundings. Marine biologists led by Sylvain Pincebourde of the University of South Carolina, Columbia, put sea stars in aquaria that mimicked changes in heat and water levels in their intertidal habitat. When exposed to warm air at low tide, the researchers found, sea stars wait until high tide and then suck more seawater than usual into a large fluid-filled body cavity. The extra fluid increases the animals' "thermal inertia," buffering them against the next low-tide exposure. The authors report the result in the December issue of The American Naturalist.