Friend or foe - small starfish

[cvu]

I saw it eat my zoa, but I think that zoa was on the way out. However this morning I saw it on another zoa frag, the frag itself is not 100 % healthy but I think it still has many life left. So not sure if I should keep this starfish in my tank.

 

[JohnBRZ]

I think they’re cool but most reefer think of them as a pest and doesn’t want them in the tank

 

[cvu]

I have no problem with most of them. This is the first one I see it covering my dying zoa and few days after, the place was clean. And only this one starfish. Just want to know if we can distinguish the good ones and the bad, or just my luck to have this particular one behaving a little from the rest.

 

[JohnBRZ]

I would just remove it to be safe or test it with a healthy zoa out of curiosity

 

[joseserrano]

Mixed reviews, but I don’t really pay attention to them

 

[drexel]

Aquilonastra (formally asterina) star. They're part of the CUC and are usually the first on the scene if a coral is in decline or dead. I've personally have never witnessed one go after a healthy coral, but there are some that can cause damage, but most of them are kinda rare these days. They do reproduce quickly, so they can chomp on your prized CCA, but I find they keep things in check.

 

[ndrwater]

Im with @drexel they can and do reproduce quickly. But, there is only so much food to go around so they typically limit themselves in number.
Keep an eye, because as Drexel said, there is a strain that can/will eat coral. Rare, but possible.

 

[Jimbo327]

Get rid of it. I hate asterinas with a passion.

If you see it on your zoas, it's probably a foe.

 

[tritonpower]

I have lots. Never seen if bother corals. I have SPS, torches, mushrooms, gonis, etc. I do not have any zoas though. Not sure about those.

 

[drexel]

I’ve had several corals (mostly frags) that weren’t healthy for the longest time and as soon as they start to go, these guys show up and clean them right up. They can be unsightly, but I’ve never seen them destroy a tank.

 

[Tangerine Speedo]

I have heard from my cousins brother, second wife's son, who works at the water treatment plant, had a friend that said "The ones with red in them can be aggressive"...
So I hear...