Help 2 Dead Crabs!

[Skelly44]

Help..

Just wanted to check I am not doing anything wrong..

I bought 4 crabs last weekend (red claw), I returned home today after being out for 5 hours and two of them were dead...

Strange thing is they were both flat on their backs on the one crab his belly shell was peeled open! I only have 12 other fish in the tank they are all fine, they are not very big and none of them would have been strong enough to do this.

Any advice would be good..

Anybody have any ideas?

 

[three-fingers]

The crabs could have turned on each other, but i've never heard of that.

Are they in fresh or brackish water and do thye have land to go on? Also what are the other fish?

 

[dizzied]

Or maybe it's just a molt.