hi, can be common yes. Domino's are one of the few that do that. About your other question- Depends on the species of clowns you get and how big your damsel is, and the clown size. More than likely that domino will defend that anemonie to the death,and not let the clowns host. Clowns are finecky enough to get to host, you don't need a stupid domino screwin up your plans.(no offence) If you want your clowns to host, get rid of the domino for sure. But do as you will. Ya never know. Good luck, Ali