urchin vs coral

[vinnyraptor]

got a piece of LR covered in zoo's yesterday. this morning i noticed my spiny urchin was very close to it and i also noticed a few polyp's fell or were cut off the rock. is this guy trying to eat them? if so how to a get him out? i also have a pencil urchin should i get rid of both?
another question, not all of the polyp's have opened and i smelled some die off in the water it came in. this was bought at that chain everyone gets steals at _etco. if some are dead what if anything should i do? im a newbie to corals but not the hobby.

 

[nycbob]

some urchins will eat corals. some will simply knock the corals off. without more info like a pic , is going to be hard to answer for sure.

 

[fishstick4sale]

yea some urchins will eat coral, some arent reef safe i would remove it if u want to keep coral or ask your lfs if its reef safe

 

[vinnyraptor]

got rif of the spiny one, will monitor the pencil and if he goes near it he's a goner too.