Attack of the Sea Urchin!

[narab]

Today we noticed some aggresive behavior from an urchin that was an unexpected passenger along with an order of live rock.  It has nearly tripled in size since we got the live rock two months ago.  It's now 2.5" long!  This is the first time we've noticed any aggresive behavior.  The picture below shows what appears to be the urchin attacking a polyp.  Should we get rid of this urchin?  If so, what do we do with it?  

[Sahin]

Cant see any pics.  

[Mr Spam]

ooo thats go to hurt that poor polyp. moving the urchin to a different tank or selling/returning him to the LFS would prevent him from damaging any critters in your tank.

[byrself]

i agree, i personally don't care for urchins, and for that very reason.  i have a black long spined that's in it's own tank with my choco chip star.  neither will have their home in my reef.  they like to eat too many goodies.  

[flaunt]

i had an urchin like that in my nano, he moved over every single rock but i never saw him eat anything that i wanted to keep, other than a patch of macro algae.  i moved him to a bigger tank mainly because he was bulldozing the smaller rocks in my 10g.

[printerdown01]

These guys eat algae... They will however bother inhabitants by bumping in to them. They also have a habit of knocking over rocks, urchins are the bull dozers of the sea -they are quite strong. He probably isn't peircing your polyp, but will bother it just by touching it. My recomendation is that you remove him from the tank in the near future... In the mean time he will eat algae and bump into stuff . I promise you that he isn't aggressivly stabbing your polyps -he might however run into them and accidentally peirce them (never heard of this happening, but I suppose that it is hypothetically possible).