thing on glass, ID?

[Pea-brain]

Hey. I was looking in the tank and noticed this little white thing on my glass. I don't know what it is. At first I thought it was a sponge but it is flat. I can't get a pic of the top because its behind a bunch of rocks and stuff. I found another lump like it on my PH but can't get a good pic. Just looks like a white lump from the top. From the bottom it looks like a frilly starfish blob. Its got what looks like 7 arms radiating from the middle of the blob, 4 big and 3 small. I haven't seen it move...

Also you may notice the fiddler in the pic. I bought it as feeder food but the animal I was going to feed it to died. Anyone have experience with fiddler in a reef setting. It can get out of the water a bit if it needs to....Anyways thanks!

Dan

Edit: fixed the pic links

 

[charlesr1958]

Looks to be an Asterina starfish, one of the few starfish that can get quite prolific in a reef tank. Should be a harmless herbivore.

As for the crab, being the little omnivores that they are, I would not consider it reef safe as it may wipe out a good many critters that life in/on your live rock. Most crabs are just a bit too destructive for my tastes.

A Hitch Hikers Guide to the Reefs

Chuck

 

[Yinepu]

I agree, it looks like an Asterina starfish to me as well

 

[Pea-brain]

Thanks. I don't have any SPS corals so I shouldn't have to worry about them going predatory. I didn't know asterinas had 7 legs though. SO far I haven't seen the crab so much. It hasn't bothered anything. It on;y has its big claw and I haven't seen it open it yet, even at the evil feeder stick, SO I think it mighta sprung a muscle or something. Can that happen to crabs? Oh well thanks again for answering another stupid hitch hiker ID thread

Dan