[davemartin88]

Here's a picture of my Frogspawn coral after our Pencil Sea Urchin spent a night munching. The white area is a circular indent that was eaten away and exactly the size of the urchin. Had to pry the urchin off and banish it to another part of the tank. Is this common, mentioned it to the LFS and they hadn't seen this but thought others might be interested in the picture.

This was about a week ago and two of the heads weren't opening as much as the others but seems to be recovering now.

Dave Martin
Leesburg, VA

[sigis]

urchins are the devil, they thrive off of any and all algea, including that light film i can see on you frogspown, the one you have probably just found the frogspawn and discovered that it was easier to bite into than the live rock and decided to keep going, have you seen it on the side of the glass ever eating the corraline with its cool looking star shaped teeth, i vote to never have urchins in reef tanks, they are algea destroying lawns mowers with no discretion between live rock and the base of an LPS coral

[Taras1]

I have a small short spined Atlantic urchin which seems to leave my inverts alone. Pencil or Mine Urchins however are notorious for munching on all sorts of stuff, including the algae you buy them for. Do your research and understand the ecology that these animals come from. Many of the inverts are opportunistic feeders; if they can't get what they usually eat, they settle for something else. That something else usually will be a prize coral.

[davemartin88]

Posting here is part of my research. The reading I did before I bought the Pencil urchin seemed to indicate it was a pretty safe addition, didn't turn out to be as safe as I thought. I thought folks might be interested in the picture of the damage.

[IceMan]

Originally Posted by davemartin88

Posting here is part of my research. The reading I did before I bought the Pencil urchin seemed to indicate it was a pretty safe addition, didn't turn out to be as safe as I thought. I thought folks might be interested in the picture of the damage.

same here, i thought they were reef safe. thx for the warning.

[Taras1]

The book Reef Invertebrates by Calfo/Fenner is a great investment to your reef library. They give really good insight to the ecology of all sorts of these critters. A lot of stuff I thought was "reef safe" turned out to be "relatively reef safe."

[Fishhead Junkie]

my tuxedo urchin seems harmless enough. i have had it for at least 6 months if not longer and the only trouble it causes is when it occasionally grabs a small piece of rock that might have a coral attached to it, but its more for decorating itself than for eating. i was actually surprised that it has lasted as long as it has...i thought they were more delicate but my lil guy is hardcore to the bone.

[Taras1]

I haven't had much luck w/Blue Tuxedos; what's the secret?

[Fishhead Junkie]

i really dont know what the secret is...i dropped him into the tank and never messed with him again. he eats whatever it is a tuxedo urchin eats...i always thought of him as a red urchin but i am color blind so i am guessing the blue color is the vertical strips seperated by the legs/grabbers. i must really be color blind!!! good lord!!!