Thanks NM. I caught the guy and took him out. he is currently in a bucket. I dont know how to identify the positive ones from the negative ones. This guy is white bodied with red outsides. He actually is about 12" long now that i can see his whole body, and about 1/2" wide.. very nasty looking dude. Should i put it in my fuge or just get rid of it? i dont want it in my tank!!!