Cannibal Long Spine Urchin?

Yesterday my red pincushin urchin died. It looked sick for the past while (losing spikes, moving around less, colour faded/scabbed looking) and was far less active. About a month ago I introduced a wrasse to my tank that later appeared to show signs of ick, the wrasse died within a week of introducing it to the tank. I removed it quickly and none of my other fish ended up getting sick from it. I wonder if the urchin caught ick when the ick eggs hatched (can urchins get ick?).

Anyway, yesterday my pincushion urchin got a resurgance of energy and moved from the rock he was focused on for the past week and walked over to start cleaning the glass. My long spine urchin followed him over and eventually climbed on top of the pincushion urchin and stayed there for a while. The two urchins interacted for the many months that they were in the thank together and were fine with one another. After the long spine finally unmounted the pincushion yesterday the pincushion kept about cleaning the glass for about 5 minutes and then stopped moving eventually fell off the side of the glass onto its back. I went to roll it over and then I noticed that there was a giant hole in its body, Could my long spine have eaten the pincushion and killed it? Or would the hole be a result of the fall and its sickly condition causing it to be easier to break? After the wrasse died last month the long spine urchin was eating the caucus before I was home to notice it was dead and take it out. Do I have a killer urchin and should I get rid of it?


Thanks

 

No. Your urchin cannot get Ich.Sounds like starvation to me.Try feeding it pieces of nori.

 

Ich is a fish only disease ..While it can hitch a ride on inverts it can not infect them ,but thats a totally different discussion .
Urchins really need a well established system(i'd say 2+ years at least),,they love coralline and like vinny said .nori/seaweed strips.
Also i have seen mine on top of broccoli nubs that are left behind from the tangs.