I've found an asterina star in my tank. I heard today that there is a good one and a bad one. The color of the mouth black or, white determines good or bad. Does anyone know which is the good asterina? My buddy has them in his tank and wer'e pretty sure it is demolishing any zoas/polyps he adds to his tank. I have both and don't want to risk it. I'll probably put it in fuge til' I hear from someone.