A species of sea star (the ochre star, Pisaster ochraceus) has figured out a novel way of keeping cool on rocky shorelines. The animal literally soaks up chilly water during high tides to protect itself from the blazing temperatures that persist when the tide goes out, scientists announced today.
(Based on the article Sylvain Pincebourde, Eric Sanford, and Brian Helmuth. An Intertidal Sea Star Adjusts Thermal Inertia to Avoid Extreme Body Temperatures. The American Naturalist, 2009; 174 (6): 890 DOI: 10.1086/648065)
"Sea stars were assumed to be at the mercy of the sun during low tide," said the lead study researcher Sylvain Pincebourde of François Rabelais University in Tours, France. "This work shows that some sea stars have an unexpected back-up strategy."
"This strategy only works when the sea water is colder than the air," said study researcher Eric Sanford of the University if California, Davis. "Ocean warming might therefore break down this buffering mechanism, making this sea star susceptible to global warming. There are likely limits to how much this mechanism can buffer this animal against global change." Full story
Another recent study, however, found that P. ochraceus might grow faster as the water warms. (See Sea Stars Grow Faster as Water Warms by Stephan Reebs, Natural History Magazine, article posted on livescience on 9/18/09.
(Based on a study conducted by Rebecca A. Gooding and Christopher D.G. Harley, University of British Columbia, Vancouver and published in the Proceedings of the National Academy of Sciences.)