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I found this crab a mnth ago in my tank... Maliit lng sya, now ganito n...please pa help pa identify and if safe sya sa reef and with fish

Hi hotshots,

Unless otherwise advised by the experts here, I've always found various forums to see crabs as opportunistic feeders - they eat fish or corals that are easy prey...eventually, especially when they get bigger. Unless you have a specialized tank setup maybe you could return it to the LFS or put it back to the sea if that's where you got the rock that it came with.

Regards,
Danggit

I don't know about the id.
I have at least 3 crabs in my tank, 1 looks slightly like this, 1 is lighter color, and I think 2 pure black.
all started as small but now they have grown, some about 1inch body.
they are all elusive, not seen often. i see them eating/biting on the rocks, maybe eating detritus.
I think they eat fish only if the fish is dead or weak.
i didn't put much effort in catching them because i think they are reef safe or fish safe(at least for now).
the only thing is they are knocking down my coral frags.

hotshot its up to you to observe, if coral safe or fish safe.
if in doubt just remove it. good luck catching it!