I bought several Zoa colonies from a friend a couple months ago and I obtained them for a great price. They did really well for awhile but then refused to open up. Lately, they have been deminishing away and went from many heads to just a few. My first thought was Nudibranch so I got the trusted magnifying glass out and sure enough....there they were. I have picked out a fuzzy green critter, a long thin spyro looking piece of rice critter with tentacles, a tiny orance looking star fish critter, and several green with brown spotted critters on or around my Zoas, all of which I believed to be the dreaded Nudibranch. I have been picking them out all week with tweezers and have been keeping an eye on them with magnifying glass in hand. I noticed my Mushrooms were not swelling and knew something was bothering it. Last night, I looked under the Mushroom Colony and found a spider. This thing had large pinchers coming out by it's mouth (it did not look like a crab) and scared me. I've been sticking my hand in there since I started the tank. 1.) I'm allergic to Spiders and 2.) I'm pretty sure I wouldn't have the Antibionic on hand to treat myself if I did get bit if there is even a cure for that. Does anyone know of anyway to kill this critter without physically removing it? I am off tomorrow and am going to put peroxide and revive on my Zoas to take care of the Nudibranch problem and will be moving them out of the bio cube and into the 95 gallon tank. But the spider (?) is my big problem. I ran to get my tweezers and net but he was already gone so I couldn't catch him or get a picture of him for someone to help with identification. What I do believe is he probably came in on the Indo Pacific Zoas I obtained, he is white, has pinchers, multiple legs, and I believe he is living under the Mushrooms. I surfed the net and looked at images of the Teddy Bear Spider, Zoa eating Predator spiders, and sea spiders. None looked like it. I did find a picture on the internet that resembled him but it was a land spider not saltwater. Can anyone help me on this? it would be greatly appriciated and thanks in advance for any suggestions.