Ritteri vs Pencil Urchin

[lapin]

My Ritteri was suspended between a rock and an old outcropping of a monti. Its about 12" diameter when stretched out. I noticed this morning it looked a bit deflated and was only on the monti point. It has not tried to get its foot back over the gap yet today. Looks a bit deflated. It did however take its bi weekly lunch. While feeding i noticed a clean line on the rock under where it was stretched. Looks like my urchin was eating and passed underneath. Has anyone had an urchin sting a Ritteri?

 

[reef lover]

Ive never had it happen but if the nem if healthy it should recover quickly.