Starfish Bulk Up to Cool Down

How do starfish keep cool when lying on the sand during low tide?  Dr Sylvain Pincebourde and colleagues at the University of California, Davis and Bodega Marine Laboratory, Bodega Bay, California, studied starfish (okay, sea stars) in an aquarium, replicating tides and environmental conditions.

They discovered that a starfish will ingest cold seawater to lower its body temperature before a hot day on the beach.  Sucking up water large amounts of water increases a starfish’s body mass, which means its body temperature increases more slowly.  Pretty cool!

Infrared photo above by B. Helmuth and S. Pincebourde shows cool areas in purple and warm areas in red, via BBC News.