It took several weeks to locate my only isopod that I have in my tank. I have fish and snails so a predator isopod would be a NO. I have read that the non-predator isopods can curl up in a ball. It is shown in the fourth photo curled in a ball. I would like to know if there are any predator isopods that can curl up in a ball. I'm guessing the answer is no. I also read that the non-predators have smaller eyes and that the eyes are spaced farther apart -- almost on the sides of their heads. Relatively speaking, I'm guessing that this isopod's eyes are farther apart than the predator cousins. I would hate to get rid of a Sphaeromatid Isopod, but I don't want any Cirolanids feeding on my fish or snails. Right now the isopod is in an isolation tank