Is this pest eating my Hammer corals?

[Twosixpax]

A month ago I bought several branching hammer corals and for a few weeks they were doing very well, until about a week ago when they began to recede to the point there was very little flesh visible. Tonight I captured these images while checking the tank under red light - any help identifying them appreciated. The only thing other than fish and coral I've put into the tank intentionally are Berghia Nudibranchs several months ago to tackle an aptasia outbreak.

Thanks!

 

[Cheezle]

Probably. I know my asterinas have been eating my corals, SPS and LPS. The hammer in my picture is gone. Trash em if you can, I got a harlequin shrimp but haven't noticed a decline.. yet.

 

[bluemon]

They are asterina stars, and my opinion is that they will not actively hunt healthy coral.

They get a bad rap around here, but 99 times out 100, they are only eating coral that are already dying.

And I've never caught mine eating anything but algae and microfauna even when I've had some dying coral.