There is conflicting reports on the 6 legged mini star.. If you read of Garfs site about reef pests you would take it out of your reef for sure.. If you have them and are seeing no damage I see no reason in not keeping it.. If you had a harliquin shrimp like woodstock he would eat that as food heheeh...
Its an asterina mini star fish. The seven legged stars are what Leroy reffers toon GRARF's website.
I have them in with my sps and they havent even touched it.
I have them in ALL of my tanks infact with no adverse effects whats so ever.
The seven legged problematic mini star fish have two leggs that are MUCH more pronounced and elongated from the rest resembling two fangs (at all times including right before and just after they split).
Aserina stars CAN HAVE seen leggs but this means they are in the process of subdividing so dont freak.
They are devtriovores. If you find them on your corals your coral is on its way out. They eat dead tissue from them.
SO if you have an infected coral they may infact help heal it. sort of like maggot therapy. I know EEEEWWW bu they if it works! LOL!!