glazer,
I do not deny, and never have, that there are problematic species, or individuals, of this Asterina star. I encourage people to keep a close eye on them. But I challenge anyone to identify what species of Asterina is involved from a mere picture, and which eats algae or corals, or even possibly when. Color and size are generally irrelevant characteristics to seastar taxonomists, especially when dealing with species that reproduce by splitting.
I can assure you that none of this (from GARF site):
You will often notice this small starfish on the glass just above the sand. This predatory starfish can be distinguished because it often has two or four shorter legs. During the last year we have been noticing a new starfish in our reef aquariums and it seemed to be dividing. Several people noticed this type of starfish in their aquariums and they have wondered if they were harmful. Well the small, flat, large body starfish are definitely harmful to SPS corals.
Does anything other than cause needless and unwarranted hype.
I will send the photo on GARFs site to a seastar expert, and see if he can give me a definitive species and what it eats. Perhaps will do the same with the photo above. The one on GARFs site is different than the one above (and other people have reported this difference too); however, GARF states that all of these small stars will eat corals.
The only thing you can do is watch them. If you have a problem, by all means remove them. But they are not all problems, and they do not all warrant removal. I have had the same experience that many reefkeepers (including those with SPS corals) have had.
However, I am expressly opposed to the generalization that all of these stars are coral eaters. They are not. And I find it alarming that various sites propose the removal of any animal when there is no evidence for harm. I do not believe in hype. I do not believe it helps a tank to work people into an unwarranted frenzy of removing them. I do not believe in encouraging people to buy things like harlequin shrimp to remove something that may be doing no harm.
These are not animals that are randomly wandering over the glass until they accidentally run into a coral. MOST people have those that eat algal and bacterial films. The one's I have are reproducing nicely, without any SPS corals around.
Now there are those that would propose they are opportunistic, and will eat what is available to them. Perhaps they are just really really hungry. There are those who would propose that they can smell unhealthy corals, and will be drawn to them, like flies to a kill (and my brittlestars to the dead snail in the tank now) perhaps long before we recognize them as ill. There are alot of proposals about what they are doing, and how varied their diet is.
I am well aware of the comments on Asterina sp stars. I can post an equal number of threads from people who haven't seen them harm a thing.
And, IMO, GARF SHMARF. I think Dr. Ron Shimek said it best:
Frankly, I take everything I read on the GARF web site with a grain of salt about 3m on a side
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You gave an idea for further research, and I gave my opinion of their information. I am entitled to hold that, just as you hold a counterpoint.
I am sorry if you took my post personally. It was not directed at you, but at the GARF site. I have no arguments with your reasons for removing them in your tank, or with anyone who believes they are cuasing problems. But I believe, had mmync gone to the GARF site, that there was a need for a very clear counterpoint. Equal and opposite.