Can anyone help ID this creature?

[tomhollett]

Hi all,

Just discovered a new inhabitant in my tank and not sure what it is. Looks like it may be an immature sea urchin, but I'm out of practice on IDing. It has what appear to be reddish to purple spikes that may have a pink tinted tips and it has been staying in this hole all night.

Any help would be appreciated as I am concerned it may be aggressive to my corals.

Thanks and sorry about the picture. I know it's not great, but I tried several shots and this was the best.

http://home.columbus.rr.com/altered/P1010349.JPG

[hystrix]

It is a rock urchin. they usurally hide during the day and forage at night. They will start to eat coraline algae if other sources are depleated. We have quite a few in our lagoon tank at work. I see you are in Columbus, are you going to the meeting on Tue?

[tomhollett]

I've been traveling this week and must confess - what meeting?

Thanks for the info on the urchin, he's poked his head out after the lights went out. Should I leave him in there or find him a new home? I don't want him eating on my corals (is that a concern)?

thanks again!!

[redFishblue]

I don't know the name of the urchin but it looks like the hole boring variety. They can chew little round holes in your live rock. I have one that looks like yours but it has left my liverock and corals pretty much alone. It eat some algae and then hides in a crevice. But what out when it gets larger.

[djquestion]

are these urchin's edible? =)