Boring Urchins
 

Sphere I am in Mexico and have seen literally tens of thousands of black spiny urchins during my dives. The bore into the rock making themselves a nice little armoured den with only their spines showing.

My question is has anyone seem this behaviour in their aquariums? Is the black spiny urchin in the trade (Diadema setosum) the same? I'd love to have one but not if its going to destroy my rock.

That doesn't sound boring to me. That sounds rad! Can't say that I've ever witnessed (or noticed) any of my urchins exhibiting this behavior.

Here on Vancouver island there is a piece of shoreline called Botanical beach. It's made of fairly soft rock and there are some neat large tidal pools that allow you to see a lot of our local marine life. One of the neat things to see is the rock boring urchins. Here they are purple in colour.

http://www.johnharveyphoto.com/Botan...oles_1000W.jpg

Ive seen tanks with the more colorfull versions , in Hawaii they have them in all different colors yellow, red, purple, and I think they bore into the rock if they cant find a safe hidyhole .

I had a Hawaiian rock boring urchin that came in as a hitchhiker and grew to full size. It bored itself a hole in one of my rocks but didn't spend much time there. The boring action is likely a response to predators, of which there are none in my tank.

Looking forward to posting a couple pictures when I get home. With my waterproof point and shoot I couldn't get a wide enough shot to show the size of the colonies.

Needless to say this would not be a desirable behaviour in a reef aquarium.

Might be a different species, I saw thousands in Cambodia and they didn't bore into the rock.