Thank you! I’m not familiar with those, but they seem similar to pincushion urchins. I’d let them clean, but keep on eye on the coral, just in case. I’d also add them to my fuge if it has hair algae or other undesirables in it. Sounds like a potentially good cuc, just keep a lookout.
I prefer Tuxedo urchins since they are the smallest urchins I am aware of for home reef tanks. The challenge with urchins which get larger is they move things around more. If your rockscape is fused together and you have few things on the sandbed that may not be an issue. It was an issue in my tank since I had an urchin which kept on moving some of my sandbed Zoa mini colonies around and knocking off shelves on my main rockscape with SPS since my rockscape is jigsawed together and not completely glued together. I now have only Tuxedo urchins and don’t have these issues anymore.
