One of my emerald crabs lost his claw and entire arm just recently. Found it one morning just lying in the substrate, with the emerald busy feeding himself with his other claw on the other side of the tank. Any ideas what could have happened? I dont' think I have a mantis or anything that could have attacked the emerald. My red firefish is also doing fine (he sleeps in a crevice, which is probably a good spot to get slashed by some not so friendly creature).
1.024, Ammonia 0, Nitrite 0, Nitrate < 5, Ca
10, 60lbs LR