The smallest mammal in the ocean doesn’t rely on blubber or a large body to keep toasty
Sea otters’ secret to staying warm isn’t in thick stores of blubber. It’s in their muscles.
Leaks in the energy-generating parts of muscle cells help otters maintain a resting metabolism three times as fast as predicted for a creature their size, researchers report in the July 9 Science.
“This could be a game changer in terms of how we think about the evolution of all marine mammals, not just sea otters,” says Terrie Williams, an ecophysiologist at the University of California, Santa Cruz, who was not involved in the study. To dwell in cold oceans, mammals must have developed ways to regulate their body temperature amid the chill. “To me, this is probably one of the clearest pieces of evidence saying, ‘Here’s how they did it,’” Williams says.
