The Reason You Should Never Lift A Starfish Out Of Water

For one thing, starfish aren't fish. There's a movement afoot to rename them "sea stars," but it doesn't seem to be getting much traction, even for a creature that's been known to grow as many as 40 appendages (it's a stretch to call it an arm) and moves by way of tiny tube feet on the underside — you know, the part that holds on to the rocks where they're most commonly found.

According to the National Oceanic and Atmospheric Administration (NOAA), a starfish — or sea star, is related to sand dollars, sea urchins, and sea cucumbers, and is classified as an echinoderm. Not a fish. Neither gills, scales, nor fins grace starfish; not even blood, cold or otherwise. Nutrients move through their bodies via salt water, pumped throughout. They're found throughout the world, but only in salt water.

Smithsonian tells us that there are more than 1,600 species of starfish with us today, though National Geographic claims the number is closer to 2,000.

Even though they aren't going to break any speed records, starfish are predators, going after invertebrates (which sounds awfully judgmental) such as clams and mussels. Starfish are also considered brainless (again, more judgment).

And those arms? Used for predating and movement and self-defense, insofar as if one comes off — for instance, to escape a predator of its own — the beastie has the capacity to re-grow it.