Strange looking critters on the glass

[Baldy]

Hello all,

This morning i woke up and was checking out my tank when i noticed 2 little things on the glass. Its kind of hard to explain, but they look like tiny starfish. theyre less than 1/2 inch across, and instead of 5 legs, one has only 4, and the other has 2. I noticed one of these guys when i was putting in the LR as well, and he only had 3 legs, around the same size.

Any idea what they could be?

[abcha0s]

I'm updating my answer. +! for the Asterina starfish. Good call Codfather.

Hydroids are interesting too, but probably not what you are seeing.

- Brad

[The Codfather]

I would say exactly that, Asterina starfish.

[High tide]

+1 on Asterina star. It will soon develop a few more legs and then split again.

[Jackie]

Asterina starfish. I have a few like that too.

[Baldy]

From the pics I found on Google, that seems to be what it is. Are they a problem to have?

[High tide]

There are reports of Asterinas feeding on coral. In my experience they are harmless and valuable grazers of algae and detritus. I have observed them eating necrotic tissue on coral (not a bad thing IMO).