Outdoors just for kids: Why octopuses don’t get stuck on themselves

2014-06-12T00:00:00Z Outdoors just for kids: Why octopuses don’t get stuck on themselves The Billings Gazette

Octopuses are odd-looking creatures. They are members of a class of mollusks called cephalopods, which also includes squid, cuttlefish and nautiluses.

Octopuses have eight arms that, if you’ve ever seen one up close, may remind you of eight squirming, slimy snakes. On each of those arms on a full-grown octopus there are about 240 suction cups. So if you multiply eight times 240 you get 1,920 suction cups on each octopus.

Those cups come in handy for grabbing prey that the octopus eats. The cups are very strong, and are way more complicated than the suction cups you may see on toy guns, darts or arrows.

One day, some scientists wondered if the suction cups are so strong, why doesn’t the octopus get them stuck on its own skin? They wondered this because, unlike you and me, an octopus has no idea exactly where its eight arms are located. That’s because our arms and legs have a limited number of places they can be; they are restricted by our skeleton. But an octopus’ long arms have an unlimited number of positions. For the octopus brain to track all of those at once would take a huge brain. Even then it might be impossible.

So if the octopus doesn’t know where its arms are and it has these sticky suction cups on its arms, why isn’t it tied up in knots, the scientists wondered? Turns out the octopus’ skin produces a chemical that keeps the suction cups from sticking. It’s a simple solution that keeps the octopus from being an octoblob.

— Brett French

Gazette Outdoors editor

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Brett French

Outdoors editor for the Billings Gazette.

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