[gandorf2000]

anyone seen this? it looks like my sea urchin is eating my LR? he sits on it all day there is a pile of what looks like crushed LR under him and "fresh" spots on the lr? Never see either of them in the sand bed... just on the rock and glass

[pmason44m]

We had a pencil urchin that did that all the time! ... then pooped the sand out the top of his head ;-) super funny... we returned it for credit once we turned the tank into a reef. They are great fun, but will move/unsettle any unsecured thing in the tank. Glue your rock or an avalanche is coming ;-)

[Okayamapiper]

Urchins will clean live rock. Sometimes they clean it so well that it is white when they are finished. The long spiny urchin will actuall bore a hole into LR. Whenever I go to tidepools in Kochi, Japan the rocks look as though someone had used a drill and at the bottom of each hole would be an urchin.

[pmason44m]

James,

I'm really glad you posted this about the long spiny, I was just about to get one for my small reef tank... in an attempt to see if it would eat the caulerpa that keep coming back.

Do you think it would eat this? (another thread, scroll down a bit for pic)
http://www.reefbuilders.com/forums/r...-caulerpa.html

And do you think they are actually "reef safe"?
Thanks in advance!

[gandorf2000]

I really doubt it....urchins are normally sand sifters I believe

[Andrew Rhyne]

Urchins are herbivores, most eat smaller turf or macroalgae. Some bore into rock. Did you buy the urchin or is it a hitchhiker?