Hitchhiker ID Please?

[subman]

Originally Posted by ashr

They are good

I would say "good" they can be beneficial...but reproduce rapidly and can soon take over and become a nuisance.

[MrGoodbytes]

Some have reported them munching on coral but I've never seen this personally. This, however, doesn't mean it doesn't happen. It depends on the species you get. If they become too numerous, cut back on feeding or consider a harlequin shrimp :P (if you have a sustainable population).