Are they Baby starfish

[milan]

I have about 50 critters that look like tiny starfish, mostly on the glass as opposed to my live rock. The number of arms vary from 4 to 6.These appeared about 5 months after I bought 1 sand shifting starfish. I'm sorry I don't have a camera to post pictures.
1. are they baby starfish or something else?
2. Should I remove them from my tank?

Thanks for any advice you may have!
Milan

[UnderwaterExotic]

They sound like the ones that eat coral!! Careful!

[dgphelps]

Do a search on Asterina folium. They are sometimes accused of feeding on corals, but I think that it feeds on dead or dying coral flesh. So if a coral was sick, it ia just doing its job (just like a bristleworm). They reproduce very easily as well.

There is a small starfish that preys on coral but from my experience the above is probably what you have. I have had them many times when starting up a tank.

I hope I wrote this fast enough so that last reply doesn't freak you out.

[dc]

Just the fact they are on your glass and not your corals I would tend to favor dgphelps post. They do seem to come out of nowhere. I got my first from IA didn't see them for a year, now I have tons.

http://images4.fotki.com/v39/photos/2/28482/235116/starfish2-vi.jpg

[rshimek]

Hi,

These are asterinid sea stars. Here is a bit of information about them.

Asterinid Stars

One, or perhaps more, species of small sea stars in the family Asterinidae are the only sea stars that can be said to thrive in some reef aquaria at the present time. The species is indeterminate; the geographical origin of the stars is uncertain, and there are numerous similar described species. Without knowing where they are from, there is no way to put a "name" on them.

These are small brown, tan or gray animals, generally not more than about half an inch (13 mm) in diameter. Flattened from top to bottom, their three to seven rays and central disk merge into one another. They reproduce asexually by fission and if there is sufficient food almost all the stars in a population will be regenerating rays or other body parts. They are substrate feeders and move around with their stomachs extruded over the substrate digesting who knows what. It is a pity that these animals are so drab. In some systems, they are quite prolific and even if they don’t thrive, they appear to be able to survive in most others.

Occasionally, some populations of these asterinids have been reported that eat either soft corals or stony corals. These coral-eating forms, perhaps a different species, seem to be quite uncommon, constituting less than five percent of the populations reported by aquarists.

[milan]

Thanks Dr. Ron & company! Special thanks to Debbie - her photo could have been taken in my tank!

If they are substrate feeders then it would seem Asterinid Stars should be a welcome addition. I'm assuming that they would turn over the and bed as they eat.

Milan

[Adonis Mt]

I don't believe they move the sand, i generally see mine (100+) on the rocks or glass. Nonetheless, i consider them a valuable addition. All positive and no negative.

I do have a question for Doctor Ron.. Is it possible that serpent stars could prey on these? About 2 weeks ago i added a serpent star (not large, probably 6" from the end of one ray to the end of the oppisite), and it SEEMS that there are fewer stars on its side of the tank, i could just be imagining things though.

[rshimek]

Hi,

You are right they don't turn over the substrate much, just cruise over the top of it.

Some brittle stars are quite predatory and could well have a taste for these little guys.