This morning I got up to find my urchin resting next to and partly on my Green Sinularia. I figured it was just resting there but decided to boot it away. When I came home from work the urchin was back on the Sinularia only it was clear to me it wasn't resting on it. It was eating it ! It took a chunk out of the second stock and now can just barely support itself. It's all black around where it was eating it. So much for these just eating algae.Here's a pic of the urchin I have, in case you want to know the type.