Little White Starfish
In the last month I've noticed some small white starfish on my glass. They are about half the size of a penny with thick legs and usually between one and three legs fully developed. I found one which appeared to have started a bunch of other legs which if fully grown would have seven legs.
Any information on these little critters would be helpful. I have no idea where they came from as I haven't added anything in over six months.
These are common and appear to be surface deposit feeders - in other words, they extend a tiny bit of their stomach through their mouths and walk slowly around digesting the world.
They are possibly a species of Asterina , but I consider that identification unconfirmed.
They appear to reproduce asexually by fission. I added the first ones to my tanks about 3 years ago, and didn't see them again until about a year ago. If you are seeing a few, my guess is you have lots.
They are harmless, probably could be considered to be microscavengers.
All I know is I could scoop a film canister full of them if you want them! They are pesky little creatures to say the least! I think they are eating my coralline because I have starfish sized white spots all over where they hang out! I can't siphon them out fast enough!
Dr. Ron, know of any natural predators?
Why not just let them be. The coralline will grow back in, and in a more natural pattern.
I would suspect hermit crabs eat them.
I got a lot of them also. They don't cause any problem in my tank.
I have had the same starfish (from what you describe) for the past two years. They have never caused any problems with the coralline in any of my tanks.
Lately, with the heavy feedings of frozen mysis, I also seem to be getting more. I agree that they are probably detrivours/microscavengers.
The spotty death of coralline seems to happen periodically in my aquariums. But it happens in multiple locations through out the tank - even places where the white starfish seldom go.
I wrote the coralline death up to lack of required nutrients and/or water conditions (ie hardness/calcium). (My calurpa likes to do this also!) At these times a small water change and the algae grows back quickly.
In summary, welcome the white starfish!!! ...they are probably tying up a lot of the nutrients that would otherwise become algae (the bad stuff) if they were absent.
Actually, these little guys are in plague proportions! They reproduce faster than they are eaten/removed. They are all over the glass, rocks, sand, and some of my corals. I actually just siphon them out and throw them in my 72 gal tank that only has rock sand and water in it (kind of a refugium). As pesky as these guys are, I can't kill them, so down to the empty tank they go! -)
There is an article on GARF's website about these starfish. For your reference, here's the link
They don't appear to be too reef friendly.
Frankly, I take everything I read on the GARF web site with a grain of salt about 3m on a side.
The ones that were described on this list and the ones that have SallyJo's panties in a twist are probably very different species. The more common species is white and much smaller. The GARF species is actually quite larger and seems to be yellow in color if you can believe the color rendering of any of GARF's photos.
FWIW, I have two varieties of these stars in my tank. One is the aforementioned beige/tan/white one, and the other is multicolored, like a marshmallow in a children's cereal or a lump of Playdoh. It is usually various shades of purple, blue, and pink, all on the same animal. This one does not appear in nearly the numbers that the other does, and I have yet to see one larger than about 3/4 the size of a dime. The other easily reaches the size of a nickel. There are some close-ups of the underside of the tan animal at these links-
The top of the star can be seen here-
I've got similar stars in two of my tanks, but (1) all of the ones I've noticed have had six arms, not seven like most of the stars on GARF's site, and (2) neither of the tanks has any SPSs. Sounds to me like there are many species of these little critters...
Last modified 2006-11-24 18:41