small star found

[MNFishGuy]

Five arms, almost all equal in length, greenish grey, about a 5 mm across, found in reef tank, now in quarantine trying to decide what to do with it - destroy, return to reef, add to FOWLR. reef has zoanthids, galaxy coral, bubble tip...

Anyone seen this thing before? I know the picture isn't great, but the starfish is small!

40 gallon tank, three inch sandbed, 45 lbs liverock, started in a few months ago, everything else going great, all sessile livestock added in last week.... may have hitched on new livestock or have been present on liverock and I am just finding it now....

[gregr]

You've got an Asterina star there. Pretty common hitchhikers- I've had them in all my tanks over the last ten years or so and there's never been a problem with them. They could overpopulate if left unchecked and if there was enough food (algae) in your tank. Harlequin shrimp will eat them but you might have to starve the Harlequin to the point where it has no choice... eat the Asterinas or die

[Ninong]

Yes, it's an asterinid. There's no way of telling for sure if it will be harmless or not but Dr. Ron Shimek estimates that 95% of the asterinids are harmless. There are many different genera in the Asterinidae and a large number of different species. Not much is known about them except that they are found all over the world.

All of the ones that I had were white and harmless. I have seen a couple of articles showing pics of tan-to-brownish looking ones that the arthur claimed ate his SPS corals. So apparently some of them are believed to be not reef-aquarium safe but most are harmless. I guess you just need to keep an eye on it/them.

Some people have experienced population explosions with these things. Mine never got out of control. I'm really not even sure how many I had at their peak. I don't think I ever saw more than a few at one time.

Actually, now that I think about it, I paid for mine. They were part of the 'detritivore kit' that I purchased from Inland Aquatics. I think they were the ones they called "micro stars" and the tiny serpent stars were the ones they called "miniature brittle stars." Anyway, mine were harmless. They did reproduce in my tank but they never got out of hand. I actually ended up with a lot more of the tiny "miniature brittle stars" but I very seldom ever saw one. I didn't realize how many I had until I took my tank down and sold all of the live rock. Boy, were there a lot of them! Well over a hundred. All in hiding. They're very, very good little scavengers and they never get large at all, just barely the size of a quarter tip-to-tip at their largest. Most are the size of a nickle.

[MNFishGuy]

Great, thank you both, I think it is going to find a new home in one of the FOWLR tanks, he can hang out with the peppermint shrimp and turbo snails in there.

[Bloodydecks]

Great, thank you both, I think it is going to find a new home in one of the FOWLR tanks, he can hang out with the peppermint shrimp and turbo snails in there.

IO had a population explosion on one of my tanks....hundreds of them. They ate my caroline algae....i tried to fet rid of them, but was never able to get them on check. Also in this same tank I had a HUGE issue with red flat worms......the never ending battle. One day my 20 gallon auto top off malfunctioned....dropped the salinity to .016....problem solved. Also killed all the coral and everything else...(fish were fine). LOL At least the worms and stars were gone LOL LOL