Starfish ‘pump up’ to cool down7

starfish_301009

One starfish has a remarkable strategy to avoid overheating in the sun, scientists have discovered.

The starfish pumps itself up with cold seawater to lower its body temperature when exposed to the sun at low tide.

It is equivalent to a person drinking seven litres of water before heading into the midday sun, scientists say.

However, global climate change may drastically interfere with this vital mechanism by increasing sea temperatures, the researchers warn.

The ochre starfish or sea star (Pisaster ochraceus) is found in the intertidal zone along the Pacific North American coast.

It mainly feeds on mussels while underwater.

During low tide it is exposed to the air and cannot move until it is submerged again at high tide.

When exposed to the warm sun at low tide, the ochre starfish can suffer heat stress.

Now scientists based in California, US reveal how it manages this excess heat in the journal American Naturalist.

Pump up the volume

“We have discovered a quite novel thermoregulation strategy in the animal kingdom,” says Dr Sylvain Pincebourde, formerly of the University of South Carolina, Columbia but now at the Fran