Hi, I had one. I'm pretty sure they're not the really poisonous ones. Mine was great but died about a month into it. My tank was fairly new - got him with my original cleaner crew. He was coming out more and more and seemed to be growing even. Then one day, it looked like he had a hole in him. And, of course, he did turn part of his body inside out - this is where the poison can come. I did have an emerald die along with it.
All along I assumed he was attached b/c of the hole. I have a coral banded shrimp that i blamed. HOwever, after more research I learned he couldve died from starvation. The tank was very new. Maybe he wasd coming out alot b/c he was in such a search for something to eat? not sure. i didnt see him the first 3 weeks i had him! Then out all the time. Then dead.
Good luck!
