Posted Thursday, June 18, 2009, at 2:44 PM
It roams the ocean floor, always ravenous, always ready to kill. When it finds its prey, it pulls it apart with hideous strength and then eats it while the prey is still alive. What is this fearsome beast? Is it a shark? A kraken? The Loch Ness Monster? Nope. It's a starfish. The most common starfish species on both the East and West coasts, beloved by millions of beach-going children, are actually mighty predators.
Starfish aren't actually fish-starfish are invertebrates with no skeleton and no central nervous system. (For that reason many people prefer to call them "sea stars," but I'll just stick with starfish here.) Like sea cucumbers and sea urchins, sea stars are echinoderms , invertebrates with spiny bodies and little suction cups called "tube feet."
In starfish, tube feet line their underside , acting like tiny legs that glide the starfish slowly over the ocean floor. The tube feet also act like tongues, licking the bottom to sense where something tasty might be hiding. Since starfish don't move very quickly, they have to eat animals that can't get away. (No need to hide the children-people are way out of a starfishes' league.) Starfish are especially fond of shellfish, though they certainly don't balk at a bit of cannibalism. They aren't fast, but they're very, very strong.
When a starfish finds, say, a nice plump mussel, it crawls on top of it and uses its tube feet to pull the mussel slowly apart. Starfish mouths are located on their underside, in the middle where all the legs join. They don't have jaws, but they do have acidic stomachs. So once the delicious soft bits of the mussel are exposed, the starfish vomits out its stomach, slaps it on the mussel, and digests away while the mussel is still alive. Full digestion takes hours to days. When the starfish is done, it sucks its stomach back in and glides off in search of its next victim.
If you're still not convinced that pretty symmetrical starfish are the Godzillas of the sea, check out this time-lapse video (starfish at 1:30) of desperate brittle stars and clams fleeing from a sunflower star. Or this video of a normally sedate abalone sprinting across the rocks. Though I would never cast aspersions on Patrick from Spongebob Squarepants , I do think that beachside hotel art would be greatly improved by a little ecological correctness. Any volunteers to paint some starfish-induced violence in pastel?
Photograph of a starfish by John Foxx/Stockbyte/Getty Creative Images.