Asterina star fish ..Cool ? Maybe Ö.??
If the conditions are right for them they can multiply faster then rabbits..No joke..Only Harlequin shrimp will control them and the shrimp will only eat starfish so having the shrimp[besides price] can present its own problems...
I have them in my tank and remove what I see when I see them.They will never be completely gone for me..Not really cool anymore for me ...But also not as overwhelming in my tank as I have seen with others Ö.