Is this an asterina?

[Frasercm]

Is this an Asterina starfish and if so is it eating the zoa? Should I remove it? If it is it’s been in there for a month now (new zoa rock from friend) and I’m only seeing it now (sorry for the bad photos)

 

[Picassoclown]

Looks like it! I would remove it, personally. But some people keep them and feed them to their harlequin shrimps.

 

[WalkerLovesTheOcean]

Yep, that's an Asterina. Chances are if you see one you have more. Remove it to be safe! I keep them in my tank just because it's too much effort to remove every single one of them. I haven't noticed any consequences from this but it could all depend on the type I have if I understand correctly.

 

[RabidDragon]

Yes. Its my understanding there are a multitude of different species of Asterina starfish, some safe others are not. I've had them in my tank for at least 3 years now, got in as a hitchhiker. At one point they hard risin to plague like levels. I obtained a baby Harlequin shrimp and it took it a full year to lower their levels down enough that I was worried about it starving to death. No other problems... haven't bothered any of the coral. Its been a year since I gave the harlequin back to the LFS. There are still some in the tank and their numbers are very slowly climbing but you still have to search for them to find one during the day. At night you can see a few on the glass.

 

[ISpeakForTheSeas]

Is this an Asterina starfish and if so is it eating the zoa? Should I remove it? If it is it’s been in there for a month now (new zoa rock from friend) and I’m only seeing it now (sorry for the bad photos)

Yes, Aquilonastra star; I would say based on the coloration (which is definitely bot the best way to ID these, unfortunately) that yours is probably not reef-safe, especially with how it's interacting with the zoas there:

Aquilonastra starfish (known in the hobby as "Asterina") - some species are fine/helpful, others have been known (at least when in large numbers) to go after corals (almost always zoas).

As a general rule, if the top of the starfish is primarily black, or if it has red/orangish spots on it (like the star in the link below), then it may be harmful:

Evidence of (some) "asterina" / aquilonastra stars eating (some) zoanthids

I had NO CLUE, but figured a few dozen stars would feed a shrimp…guess I was wrong.. added: that’s what I get for inadequate research before purchase I can’t afford $20/week to feed a pair of shrimp, looks like I need to find a tide pool somewhere… thank you...

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