So what are you going to do with the shrimp when the stars are gone?
Asterina stars are in nearly all cases HARMLESS. You can not determine, nor can seastar experts, a harmful species by counting arms or looking at size or color just in the tank. Maybe microscopically, or, more likely, with DNA.
Nearly everyone has the stars, and relatively few have trouble. If you had the "bad" sps eating one's they would not be on your glass and rocks....they eat corals, and would be eating them now. Believe me on that.
Most are harmless, even desirable bacterial grazers. You can probably sell them. Actually, I am pretty darn sure you could.
I repeat. You can not determine easily what is bad and what are OK based on the number of arms or color. Don't be drawn into a delicate animal like a harlequin based on this "story" that these stars are all bad. Behavior is critical. Many get a bad rap because they are drawn to a dying coral long before we know it and they clean it up. But predatory stars would be on your SPS corals...and NOW. Not wandering the glass and rocks.
But you really must make long term plans for what you would feed a harlequin shrimp once the stars are gone. That requires research. PLEASE DO NOT buy Linckia stars to feed to these shrimp. If anything, buy chocolate chip stars, keep them in your sump, and cut off arms as needed while allowing the whole animal to regenerate. Sounds wacky but it works and is kinda cool in a wierd way. If you wish to use Linckia stars, please freeze them and cut off only one arm at a time...they have enough pressures on them in the wild. We should try and make the most use of one that we can.
