What happened?

[Octoloco]

Found this 3 legged crab at Mukilteo; it looked healthy but for the lack of legs. It was eating with the little feeder claw things at the front of the carapace. Any thoughts on what might have happened to the other legs?

And secondly, does anyone know what the black thing in it's mouth is in the second and third photos? Some type of tongue?? It didn't appear to be eating whatever it is so I'm thinking it was a part of the crab?.

[Linedog]

Rough life?

[Greg Jensen]

It's something he's chewing on- maybe trying to break open a small mussel with his mandibles. Doesn't have a lot of foods to choose from in his condition.

As to how he got that way, the two most common causes are a larger crab or several staghorn sculpins. Sometimes when a crab is attacked by a larger one, he'll lose some (or even all) of his limbs but still be alive, because the other crab can't quite break into the body. I've tried to nurse limbless ones back to normal in captivity- have to set them on top of their food- but they almost always die when they finally molt, because they don't have any leverage to help pull out of their old shell. With three legs this guy will be ok, as long as he doesn't lose more in the meantime.

Staghorn sculpins will gang up on a newly-molted crab, ripping off limbs with a 'crocodile spin' and swallowing them. Since they're not equipped to dismantle the body, that gets left behind.

My guess would be a bigger crab got him. Those attacked by sculpins usually bleed out because the limbs often don't break off in the right place for it to clot up properly.

[Octoloco]

Thanks Greg!
I felt bad for the little thing, though he was eating like there was no tomorrow............

We thought maybe an octopus was wrestling with it the way the legs were torn off but your answer makes more sense.

It's a brutal world down there.

[Grateful Diver]

I once watched a red rock crab grab ahold of a kelp crab and ... holding him with one claw ... ripped one of his legs off and ate it. Talk about harsh ... imagine being forced to watch while something eats one of your legs ...

... Bob (Grateful Diver)

[Octoloco]