Something is eating my crabs.

[t11t5]

I have had 4 red scarlet hermits, 2 red crabs, and a porcelian crab all get torn apart. Can someone help me determine what is doing this?
Tank contains,
brittle star fish
sallylight foot crabs
emerald crabs
pepermint shrimp
camelback shrimp
coral banded shrimp
long spined sea urchin
pencil urchin
yellow watchman goby
tomato clown
4 damselfish
green chromis
blue leg hermits
arrow crab

 

[yeffre kix]

Pretty tough to tell from what you've said. How are you finding these dead animals? Do they appear to be eaten or just torn apart? You sure you not finding the exoskeleton thats been shed as they grow? Could be a preditor you picked up as a hitchhiker and don't even know you have it. Seems like a fairly harmless list of inhabitants you gave.

 

[ctgretzky9]

What size is your tank? CBS are usually not tolerant of other shrimp, but as usual there are always exceptions...keep an eye out for it.
As fas as your problem, I agree with yeffre...sure it isnt the molting exoskeleton you are seeing? They look exactly like whatever it comes off of. Have you seen any of these ones that died or looked for them?
Other than that, maybe a hitcher?