Please tell me this is not a asterina...

[ChrisPPolys]

I’ve had no problems with them in some tanks, pest in others…
I have 4 reef tanks: one is infested, one has a few, two tanks have none…no clue why
…if it were me, I would relentlessly remove every last one I see for the foreseeable future,…better safe than sorry

does the OP mind if I respectfully ask approx age/experience ?

Sounds like the perfect scenario for a harlequin!

 

[ChrisPPolys]

I’ve had no problems with them in some tanks, pest in others…
I have 4 reef tanks: one is infested, one has a few, two tanks have none…no clue why
…if it were me, I would relentlessly remove every last one I see for the foreseeable future,…better safe than sorry

does the OP mind if I respectfully ask approx age/experience ?

I’ve seen posts in my local reef club asking other hobbyists for some Asterinas to feed their harlequin. When I had my harlequin it was my favorite tank inhabitant they really look other worldly and have quite the personality. I’m just restricted for space with my 32 gallon unfortunately ):

 

[EeyoreIsMySpiritAnimal]

If you have a 90 gallon just buy your harlequin a chocolate chip starfish lol

Been there, done that, got the tshirt. Lol

 

[Ollie67]

I personally removed the one I had in my 13.5 pretty soon. I just don't want to risk it for any future corals as they can multiply quickly and it's a small space. I found one yesterday the same as your picture. Just took the guy out of the tank, he was sitting right on my return nozzle.