Are these baby star fish?

Ok so my son and his wife set up this saltwater tank about three years ago. One of the first things they got was 1 starfish that including the legs measures maybe 4" across. Then about a year ago we started noticing these tiny star fish all over the sides of the tank. They are only about 1/4" in size and they just appeared that size. Where did they come from? Also they don't seem to grow. Is this a very small type of star or do they just take a long time to grow? Please excuse the looks of the tank. They don't take very good care of it. I have nothing to do with it.LOL

No Thats as big as they get. They come on Live rock or anomones.

I agree. Not a baby start fish. They show up all the time in SW tanks.

Those are asterina stars. Very beneficial to the tank. Great detritivores

ok thanks all.

They're asterinas. There's a thousand opinions on whether or not they're good stars, because narrowing down exactly which species it is is almost impossible. They breed prolifically. My experience with them... I consider them nuisance. They also seem to eat coralline.

Should we take them out?

I always took them out . They tend to eat Coralline algae and Corals ,

Well, that explains the little dried out stars I had on my (previously owned) tank when I got it! LOL! I was wondering what those were! :P

lifeisgood wrote:

I always took them out . They tend to eat Coralline algae and Corals ,

coralline yes. As far as corals go there are MANY species of these. Some eat coral, and some don't. If you can take them out go for it, but for most people harlequin shrimp are the only option. Especially once the colony has established. Good luck, I just leave em in.

I pick out everyone I see regardless of specie. I've had many reef tanks and up until
recently never had a problem with these stars then one day about 5-6 months ago I started seeing SPS's colonies disappear they were literally eating them like corn on the cob for lack of a better way to explain it, so I started picking them out with tweezers and soon realized that wasn't going to work on a 180 gallon tank with well over 300#'s of LR so I bought 2 Harlequin shrimp it took them about a month to wipe out the star population, there has been no more damage to any SPS or other coral. however Pope is right theres many different species the ones that I was having trouble with were not uniform like the picture above they were misshapen usually with only 3-4 legs the stars that had 5 legs were green. I don't take any chances now when in doubt I take it out!
here is pictures of the ones I know eat coral.

here is a picture of an Acan eating a star.


looks like Acans are good guys to have around:)