Don't be fooled by their playful shape and colorful exterior. Starfish, or sea stars as they are otherwise known, are carnivores waiting to feast on other sea life.
Most sea stars have the ability to consume prey outside their own bodies. Using small, suction-cupped tube feet, they pry open oysters or clams, and their sack-like cardiac stomach comes out of their mouth and fills up it's prey's shell. The stomach then wraps up the prey to digest it, and finally pulls it back into the body.
Did you know that marine scientists are trying to change the starfish’s name to sea star? They’ve decided to change it because the starfish is not actually a fish, it’s an echinoderm (related to sea urchins and sand dollars). In fact, the starfish doesn’t even have a brain or blood. Their nervous system is spread throughout their body and their “blood” is filtered sea water.
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.
