So, I looked in my tank today and realized my sea urchin is eating a fish! I am sure this is not the only one since fish have been disappearing. Attached a pic. Is this normal? The thing is massive and I am thinking about getting rid of him.
It is crazy because I've had this urchin for a long time (almost 2 yrs) and never had any issues with it. I've always had fish "disappear" but never seen him actually eat one. On top of that, how did the fish even get underneath him? There is so much turbulence in the water. Either way I think it's time for him to go.... here's a vid of it: http://www.youtube.com/watch?v=F90D950is8M
Your fish died from other causes and your urchin is being a opportunistic eater. In the wild fish will hang out close to their spikes for protection. Urchins have one eye and move far too slow to catch and eat any fish period, not to mention they can't "catch" a fish anyway. You need to figure out what is wrong in your tank to be killing the fish that your CUC (urchin) is disposing of. Be thankful for your urchin, without it your ammonia would be off the charts
Actually, I think it IS possible. I have two urchins. One has very small fine (long) white threads that come out between the spikes. I can easily see a fish sleeping and the urchin attaching itself to a fish while staying "planted" to live rock. Fish gets exhausted and stressed then disappears.
Until you posted this thread, I have had fish "vanish". I am talking about 3 inch tang. and a 2 inch clown. The fish were healthy, eating good and good color and "poof" GONE.
Yes, it is possible that I have a Mantis shrimp but I don't think I do as I recently broke down the tank and left the LR out for 24 hours. I think I am going to get rid of my urchins - although they do a great cleaning job.