What is this????

[sundance]

This white thing (looks brown but it's a white with a bit of tan in color) came with some live rock I jsut got. What is it and is it good or bad?
Thanks

 

[bang guy]

Great pic!!. Looks like an Asterina starfish. Most are harmless, some eat SPS coral.

 

[steelchromis]

I have two that came with my LR, they eat algae. Bang, what does SPS Coral stand for? Soft Poylp Skin?

 

[thomas712]

That is a great pic, anyone else notice the hydroid jellyfish to the lower right of the star.
Thomas

 

[bdhough]

Is that a jellyfish? Wow. Such a great close up. Yes its an asternia star and you may never see one with all his legs I have a bunch and they are all shaped like yours.
SPS=small polyped stony coral....
LPS=large polyped stony coral....

 

[spsfreak100]

Originally posted by bdhough
SPS=small polyped stony coral....
LPS=large polyped stony coral....
The proper name is small polyped scleractinian (scleractinian is the same thing as stoney, but it's more "accurate").
As Bang Guy stated, it's an Asternia sp. Most are reported for eating coralline algae, but a few species, which usually don't come up in our hobby, are known for eating SPS polyps. If you see these stars bothing any corals, by all means remove it.
Graham

 

[steelchromis]

Thanks for clearing that up.

 

[sundance]

I was hoping someone would see the other critter in the picture and ID it. So unless I see them on coral they will be OK?
Thanks all.

 

[sundance]

How big do they get, the star and jelly in the picture?

 

[sundance]

I just looked and I have a whole bunch of the little jellyfish things. It was said the starfish are OK as long as they stay away from the coral. What about these little jellys, do they stay small like this?