That is my Halloween sea urchin. He is a type of tuxedo urchin and lives with my regular tuxedo that’s about half his size. He looked really sick when I got him from a LFS near me. He had almost no spines and wasn’t moving much at all. They were selling him for $7.99 so I bought him home hoping to save him. Now he cruises my tank all day and night and he’s fast. Between my 2 urchins and my fox face and yellow tang , they really keep the algae at bay. I’m a heavy feeder so it works well for me. There’s always stuff for them to Eaton between feeding timesLooking really good! Methinks they like it.
What is this in the 6th picture?