Hundreds of little starfish

[kcinminni]

I have hundreds of tiny little starfish in my tank and there are more every day. I'm not sure where they came from and they keep the glass clean, but I want to make sure they are not harmful. Two questions:

1) Will they harm my corals?
2) I have a Mandarin that is thriving--will they impact his supply of critters, or pretty much just focus on the glass?

 

[Len]

Are these near-white with broad legs? If so, these are fairly common and usually harmless, being detrivores or algae grazers. However, some people have suggested that some species will eat corals. If you're concerned that these stars are eating corals, a few hobbyist recommend harlequin shrimps which consumer starfish. If your corals are doing fine, however, I wouldn't worry about it as most of these tiny stars are beneign. Since you said they are mostly on your glass and keep it clean of algae, I'd bet they are algae grazers.

They shouldn't compete with Mandarin for food, but they might be competing with 'pods for food which will have an effect on food availability for your Mandarin. However, if the Mandarin is still nice a fat, then it might not be a problem after all.

 

[taikonaut]

IME, they are harmless.

 

[Brutuscz]

I think they may be known coral eaters. I would check www.garf.org and look under aquarium pests. They have pics of the bad types. If they are those types...get them out!!!!

 

[KanUCme]

I have several of those, they have various number of legs and range in size. They are pretty neat and tend to hang out on the glass and eat algae, either that or they are kicking it in the grass having a starfish picnic! I haven't seen them be destructive.... yet :?

 

[Len]

There are numerous species of tiny reef starfish and most are harmless IME. A select few are reported to eat corals, but I have never encountered them myself. The best thing, as I've said, is to see if any corals are being harmed before you worry.

 

[taikonaut]

Again, almost all are harmless. With the number of starfish in my tank (hundreds), they hardly ever make any dent on my coral if they are eating it at all.