This orange crab good or bad

This is the second one I found hitchhiked in tank. Gave this one in sump should I put back. Only see them at night never see them during day

 

every crab is a good one until he's see's something he likes to eat, some fish a coral or two then he's not so good. I really can't say if he is one of those or not.

 

I'd keep him in the sump. He's got pointy claws, a sign of a predator. But even the cutest, seemingly well behaved crab has a demon inside, the demon of opportunity. It's not a question of if the opportunity will arise, but when.

 

Appears to be a member of the Xanthid family, one of the most destructive hitch hiker crabs in the hobby. While I can't guarantee that it actually is, I do agree with the above posts. IMOPE, all crabs are opportunistic omnivores, including the well-known emerald and sally lightfoot crabs that are sold as reef-safe scavengers and algae grazers. While they may be content with algae and tid-bits of leftover fish food as young juveniles, they will want - and need - a lot more meatier items as they mature, even if it means killing tankmates.

 

Thank you all. I will keep him in sump and keep an emerald crab company. THe emerald is in there because he did not touch one piece of bubble algae like I wanted him to