The You Tell Me Poll

As a new and proud owner of a lovely Montipora Undata you can imagine my nerves when I saw my halloween urchin mounted on it as shown just a day or so after placing it in my aquarium. I was tempted to remove it but I let it be and snapped this picture. Time for a little poll - Do you think it munched on the coral or the base rock below? I will post a follow up pic later today.


Ah oh. This doesn't look good.

 

Well I voted no simply based on the what appears to be polyps present on the coral.

Of course a dead give away would be loss of tissue.

If the urchin in indeed not eating the tissue perhaps there is a small amount of algae on the base?

 

I voted no also

I believe it would not venture onto the living tissue but will browse for anything it can find on the surrounding rock

a bonus, is at least in this case, either or both are easy to capture and relocate

no trap required, roll your sleeves up, and take your time about it, neither are great at evading capture

LOL?

 

I say no as well mine from time to time get on my corals and makes them mad but never hurts them.

 

I would say no as well.IME algae eaters that have been in the system for a length of time have consumed what they seem to consider yummy algaes.The addition of a new piece of rock always seems to attract them.

 

I sat and watched a turbo snail wander onto the base of some acropora and slowly eat back a quarter sized area of the flesh. It quickly recovered and I've never seen it or that type of damage again, but I believe herbivores will occasionally, accidentally, wander onto living tissue and chow a bit before they decide its not what they came for.

 

They will certainly eat coralline algae. Is there any around the base? I suppose it's possible you have an savage urchin though Or perhaps there was just some stn around the base, it was cleaning up...

 

I've seen my urchins do this same thing many times, and on occasion it seems they edge of the coral encrustment suffered a little collateral damage, but nothing which made me feel the removal of the urchin was warranted. Seems they were eating off the rock/skeleton, and drifted a bit too far the other way. Had they actually liked the coral, they would have kept on going.

 

I think they are just like the large turbo snails and will bulldoze through anything. I bet it took some tissue and left a mark.

 

I had similar issues. They are eating the good algae around the coral that came in on the mariculture plug. However mine also decided to keep going and eat 95% of one of my montipora colonies... It left 4 polyps.

On a side note, I would highly recommend getting rid of that mari plug. Most important reason being that the mix they use has a high air content and leaves some great crevices for bacteria... however a majority of the bacteria in there are already dead and decaying which typically leads to the coral skeleton turning black from the inside out and the coral dying due to bacterial infection. Cut the plug in half and look and smell it and then tell me if you want that under your encrusting coral. Second reason being that you run a slight chance of catching some mysterious bacteria that takes over your tank. Ive seen it happen before to multiple people.