Question of star fish or sea stars

[FamilyReef]

I have a small tank a 20 gallon, I know nothing big. I would like to know I found these white wierd shaped stars in my tank. I just got into zoas as they are called. ( I wonder why they call them that) and I would like to know if they stars are harmfull or not. I never had a reef before just fish only when I was single then all the fun begins. :arg:.

Any idea what they are called?

Thank you

 

[ryangrieder]

asterina starfish. They do nothing. Not harm corals really, but also don't eat algae

 

[PetShopBoy]

are they greyish, white? if they are, they may be asterinas. I had them before. they didn't bother my LPS but they seem to like to attach to my SPS, eventually bleaching them out.

 

[basiab]

asterina starfish. They do nothing. Not harm corals really, but also don't eat algae

I wonder how they live.

I found this in an article:

Asterina sea stars have been accused, unfairly at times, for preying on coral tissue. While some individuals appear to eat some desirable reef invertebrates, the problem may be a simple matter of an opportunistic predator adapting to a change in the available, preferred foods (worms, algae).​

 

[FamilyReef]

they are grey yes. They look these astraina stars you are talking about.

 

[blueink]

they will multiply from 1 to 1000 in a month.

 

[reefgeek]

harmless...enjoy your new additions