Emerald Crab mysteriously mutalated

[wun68]

I've had two of these crabs in my tank for the past 7-8 weeks now. One was eaten about 2 weeks ago and I thought maybe the other crab did it, but now I see the other one torn apart. I'm wondering if any of you out there have had any experience with these crabs living with this community:

150G Tank

4x Brittle/Serpent Star Fish ranging from 5" diameter - 10" diameter (possibly the large one?)
1x Branded Coral Shrimp small-med in size (maybe??)
1x Sally Lightfoot
2x Peppermint Shrimp
20x Red/Blue Hermits Small
30x Mixed snails Small

1x Bi-Color Angel small-med (I think its this guy, he is mean and picks on everything)
1x Coral Beauty Angel (Nice and only picks on Bi-Color in defense)
3x Yellow Tail Damsels small
1x Purple Firefish
1x Kaudern Cardinal small

I really like those little crabs cause they really cleaned holes/cracks of my live rock but I'm afraid to get any if they are going to end up as food. Any suggestions would be greatly appreciate.

 

[Innovator]

If I had to guess, either a rogue crab you're not aware of or the brittle stars.

 

[melosu58]

Also are you sure it was not a molt?

 

[wun68]

Also are you sure it was not a molt?

I just saw the crab earlier! Probably was a molt! I'm still curious where the other crab went? I'll have to check back tonight after the lights go out for a few hours.

 

[melosu58]

I`ll bet you find him alive also. Most of the time it`s a molt.