Squat Lobsters

[jimroth]

I see retailers have a steady stream of the brightly colored or patterned squat lobsters or galathea crabs. Anyone keep these? The ones I've seen are so tiny I wouldn't put them into a reef tank, you'd never see them again. Anyone keep these in a species tank, or a nano? How have the results been? They are very cool-looking but mostly commensal with another organism I think.

 

[Betta132]

I haven't kept them, but I've done some research.
They are commensal with crinoids, they live on the feather star's arms and steal its food. However, they don't require a crinoid, they're perfectly happy without one.
They're small crabs, harmless to basically all organisms. They're definitely good for tiny tanks rather than large ones, and they shouldn't be an issue to anything.

 

[Calappidae]

Certain species host different things. Allogalathea elegans are usually seen on crinoids, and Galathea balssi hang around sponges. I've seen Allogalathea elegans in person at the LFS for sale (and they're still there) but like above said, I never bothered just yet as I do not have a nano setup, and the last nanocrabs (Porcelain anemone) I threw in my 125 got lost in the overflow box (I have no idea if they're even still back there after never seeing them for a year.. might be doing pretty well with that current!)

Keeping Allogalathea elegans with a host is nearly futile.. crinoids are nearly if not flat out impossible to successfully keep long enough, I think a couple extremely lucky people got some basket stars to live a year but otherwise it's not worth it.