My tuxedo urchin didn't seem to be moving around as much as he used to, so I've been keeping an eye on him. Fearing he was dead I did an ammonia test that came up zero. This morning he was still alive, moved off the bottom about a half inch up the glass. This afternoon, there were two nassarius snails crawling on him. I moved him over to a holding bin and noticed that many "spines" were missing. I gave him a sniff:drool: and he smelled like fish, not bad at all. Do you think he's toast???