Wednesday, February 17, 2010

Sea Stars Develop a New Strategy


New research has been conducted on sea stars that has proven that they have a back up strategy that helps them stay cool when the tides recede leaving them on the rocky shorelines absorbing massive amounts of sunlight. This strategy is one that scientists were unfamiliar with, but many scientists knew that sea stars had a way of protecting themselves from the heat. Sylvain Pincebourde, the author of this study, and his team conducted an experiment to test their hypothesis that the sea star strategy has something to do with fluid-filled cavities that are found on a sea stars arms. The experiment required the sea stars to be placed in aquariums in varied water levels to have different tidal patterns. Some sea stars experienced hotter temperatures than others with the use of a heat lamp. The results showed that sea stars that experienced hotter temperatures a lower tides had a higher body mass after the high tide occurred. Pincebourde and his team concluded that hot low tides seem to be a cue for sea stars to soak up more water during the next high tide so when the next low tide occurs they will have enough water consumed in their bodies to keep themselves cool. The amount of water sea stars can hold is a remarkable amount, but the only issue Pincebourde and his team are concerned about is the fact that climate change may negatively influence this cooling strategy because sea water has to remain cooler than air for the strategy to be successful.

The source I used for this post is below and reading the full article will give more information on this new strategy.
Photo is from NOAA/National Marine Sanctuary Web Site- Ochre sea star

1 comment:

  1. That is really interesting. We will talk about the strategies that rocky intertidal organisms use to keep from drying out or becoming heat stressed in a week or so. This is not one that I had heard about yet. Thanks for finding it.

    Do they say how the seastars take up the water? Is this water in their water vascular system, or in the digestive tract?

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