Looks like a tiny starfish...dangerous?

[jbd]

These never get very big and number of arms vary. I find them in my frag tank but not in my main tank. This one is no more than 3 mm across.

 

[James M]

Aestrina star some eat coral some don’t
(Might of spelled it wrong)

 

[noahreefer]

I would take it out I saw a big fat one munching on a polyp of my zoas.....

 

[RussiReef]

Asterina star Never had a problem with it

 

[Lovemyreef2015]

It's a asterina starfish. Some eat coral some don't.

 

[JumboShrimp]

Some people like them, and let them stay, some people don’t, and pluck them out. Some people only ever notice a few, some people claim to be ‘overrun’ with them. Probably no need to panick, one way or the other. Best wishes! :)

 

[ReefEngr]

The white ones are pretty safe. The black ones might eat corals. I got a lot of the white asterina starfish in my tanks without any problems.

 

[norfolkgarden]

+1 asterina

I am in the kill it with fire camp.

Started with a few white ones 6 years ago.

Now only see black ones and believe they eat Zoas along with other things.

I also believe they can out compete my beautiful 1 year old red fromia star eating "biofilm".

I remove 2 to 5 from the tank a week. This is after 4 years of removing them.

FWIW they maybe like flatworms, in the sense that if your nitrate is high, they will explode in numbers.
My nitrate is usually high. [emoji849]

 

[jbd]

I would take it out I saw a big fat one munching on a polyp of my zoas.....

The zoa in this tank are not doing well, so maybe its the starfish. I do pick out half a dozen every week. I have never seen them anywhere but on the glass.

 

[James M]

The zoa in this tank are not doing well, so maybe its the starfish. I do pick out half a dozen every week. I have never seen them anywhere but on the glass.

You would know if the star is eating the zoas...they would look eaten

 

[DSC reef]

IME with these starfish it's hard to determine what is safe and what is not. I've seen white and dark ones alike munch on zoas. Typically you won't see bite marks on you zoas, they seem to disintegrate. The starfish almost engulfs the entire polyp as it eats it. They can reproduce fast.