Some species, as I understand it, can be threatening to zoas and smaller corals, but the vast majority of asterinas are just scavengers and algae eaters.
I will say, however, that after only 6 months of having a 9-gallon nano, I have had to do 3 or 4 "purgings" of the damn things. They multiply like crazy and tend to leave nice white dots all over my pretty pink and purple coralline (pic below). I like diversity, so I keep some around, but I eliminate roughly half of them every couple months. In a larger tank, that might be tougher, but I have a feeling that they will run rampant if not checked.
http://i.imgur.com/I9HdBaR.jpg
I don't trust them...
They may not cause any problems but they multiply so fast that they be come a issue.
I generally throw them out if I see them so they don't be come an issue.
If you're going to pull them, you might as well pull all you see... I promise, there's plenty you're not seeing.
I like 'em. Added them to my system intentionally. Valuable part of my clean up crew. Never had 'em bother anything that wasn't dead or dying. I understand there are varieties that can be pests, but the common varieties are beneficial.
Club I used to belong to owned a pair of harlequin shrimp. They'd go in someone's tank until they had demolished the population of asterina, then they'd get passed on to the next tank full of them.
If you're going to pull them, you might as well pull all you see... I promise, there's plenty you're not seeing.
I like 'em. Added them to my system intentionally. Valuable part of my clean up crew. Never had 'em bother anything that wasn't dead or dying. I understand there are varieties that can be pests, but the common varieties are beneficial.
Club I used to belong to owned a pair of harlequin shrimp. They'd go in someone's tank until they had demolished the population of asterina, then they'd get passed on to the next tank full of them.
If you're going to pull them, you might as well pull all you see... I promise, there's plenty you're not seeing.
I like 'em. Added them to my system intentionally. Valuable part of my clean up crew. Never had 'em bother anything that wasn't dead or dying. I understand there are varieties that can be pests, but the common varieties are beneficial.
i had tons of them in my tank and was just pulling them out by hand for a while until i couldn't keep up with them. I bought a harlequin shrimp that ate every last one of them. after my tank was rid of them i sold the shrimp back to my lfs.
I don't trust them...