Sunday, September 2, 2007

Starfish, not a fish

Since we were in the sea yesterday, I thought we’d stay there this week.

Let’s start with the Starfish or Sea Stars. As you probably know they are not actually fish at all, but echinoderm, closely related to sea urchins and sand dollars. Think how they get stiff when taken out of the water.

Sea Stars have no blood and they don’t have a brain! Though they do have quite a complicated nervous system. Sea Stars have spiky skin and move on tube feet. You can see the feet in the video below where one has been turned upside down. If you wait a few seconds, once the people quit touching it, you can see the Sea Star move across the sand.

Cool, huh?

There are over 1800 varieties. The crown-of-thorns starfish are wiping out coral reef in several areas of the world. I knew sea stars were predators, but didn’t know they could be dangerous. This particular guy is even poisonous, but, fortunately, the only starfish who is.


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