Last night I came home to my little hystrix doing the curl of death. I immediately went into panic mode, set up a qt tank using the original tank water, media from the original tank, and put in an air stone. I then moved the little guy over, never removing him from water. After I got him moved I tested my water to see if that was the problem. The params were Ammonia 0ppm, Nitrites 0ppm, and Nitrates 5-10ppm. He had a little pink on his underside, possibly from irritation from the sand, but if it weren't poor water conditions, what would cause the ray to go into the curls?