IMO They are your a # 1 suspects. Hermits can be evil murderer's (esp. big pretty ones). Here is why I say that, HTH:
I added 50 misc types at once to my system, along with 2 teenie tiny zebra hermit's from my LFS. It has taken about a year for it to all balance out.
Here is what I saw:
First, those tiny zebra hermit grew to huge proprtions, in a very short time. Before I knew it, they were the largest crabs in the tank. Oh how they loved killing. Getting ahead of myself, First thing I noticed was the blueleggs and the 2 zebras were on a snail killing spree, little guys would just get ate alive! Not like there wasnt plenty of algae to eat at that time either, but why eat salad when you can have steak right? I est. the death toll well over 30 of misc type snails. (they seemed to prefer the taste of margerita's best) A few of the tiny Bluelegs even murderded nassasarius snails and kept the shells as a trophy!! The two largest Zebra hermits eventually battled it out for the crab-king position, and to the victor went the spoils. I still see the empty claw husk every so often in my SB. After that the zebra hunted blue's and Im sure was startin to eye other goodies. Eventually he eneded up a permanet resident in my refugium where he has learned my hand can contain Omega one
shrimp pellets for him. Chases me around the tank if Im in there for somthing.
Eventually the
red legged hermits with the yellow faces (cute) seemed to take over the main display, there are still some small blueleggs still left in there but no larger ones.
Thats OK too cause the reds seem to be better herbavoure's and do a great job with their cleanup duties. They look pretty, and dont seem to just kill anything they can, cause they can, when larger.
HTH-Adam
