SEA URCHIN

Question
I recently bought a spiny sea urchin and watched him walk on my (open)bubble coral. Now the bubble is half open and half closed!!!!) Is he ok? Did the urchin puncture a bubble? What can I do?

Answer
Hi Mike. Sea urchins are a very debatable subject. I do not consider any of them to be reef safe! They often topple corals, walk on them and stress them out or puncture them and they will eat alot of the small microfauna that live in your tank and can decimate the population of these very beneficial creatures. They do also eat algae however it is not the green hair or the so called "bad" algae that you may have. They will mostly eat macro algae and if not provided with enough of it can often fail to thrive in your tank. They will clean your rocks of any coraline algae as well. With that said it would be wise to find a new home for your urchin. The spines are totally capable of inflicting wounds on coral polyps which can leave them susceptible to bacterial infections. If your bubble coral is well established in your tank and your water quality is very good and kept that way, the coral should make a full recovery. However if the coral continues to stay half closed up and you notice any of the polyp tissue falling away from the stony part or decaying, it may be suffering from a bacterial infection or a poisoning due to the toxins that are located in the tips of the urchins spine. Keep an eye out for any sings of brown jelly infection. These infections are frequently brought about by a fall or puncture to the bubbles in these corals. Keep a close watch on this coral and try to keep the stress down as much as possible. You can't really do anything for the coral unless it is showing definite signs of infection. Otherwise it must just heal up with time.