i had a hitchhiker, i flipped over a rock today during a water change and happened to see a starfish, size close to a silver dollar, very skinny arms, do you think it could be a brittle star, and are they good to have in a reef aquarium, i have zoas and mushrooms although im sure they are detrivores and algal grazers like most others, i couldnt get a pic because he crawled into a crevice after a few seconds and i wanted to get a look before id probably never see it again