Used to have 3 of these in my tank, they unfortunately all died. 2 died in different apartment moves, 1 year apart. 2nd didnt survive the move into new house during winter in KY.
Am lo0king to get same urchin. They came as hitchhikers on live rock, started out (first I saw them) smaller than a pencil eraser. So I dont know what their called at all.
The pic is when I had 1 in the tank, he/she was releasing eggs/sperm into the water. Was a wild experience. Can anyone ID this sea urchin please?