Lime green spounge?

[bioteacher]

Can anybody help Id these? Worried that they might be a pest. Right now it is only growing in a couple small spots. They are kinda cool looking....I know those are famous last words in the reef tank.

 

[Krollo]

I believe that's exactly what it is. I have them as well although mine are not so much in the light.

 

[bioteacher]

They aren't trouble, are they?

 

[Krollo]

Mine are not...sponges are good as they are filter feeders.

 

[Gregcoyote]

That's a pineapple sponge, they volunteer in new tanks quite often. They don't mean your tank is ready to host all types of sponges though.
I read this on another forum about their specific identity.

The term "pineapple sponge" is much over mis used. By simply looking at these things, there is no way to know what it is. Though, it may be safe to say, that it is most likely a calcareous sponge, and harmless. It takes microscopic examination of the spicules themselves, to make any sort of identification. These things could be from any one of a number of different Genera, other than Scypha, within the major group Calcarea. The Genus and species cannot be pinned down by looking at a picture. Even sponge experts won't try, without a compound microscope.

 

[PurplePolyp]

I disagree on the pineapple sponge. It looks nothing like the pineapple sponges I have come across in the past. Regardless, sponges are filter feeders so they will help the tank. If you notice a bunch of them popping up, monitor feeding a little better and throw in a few extra water changes.

 

[Gregcoyote]

It looks exactly like a pineapple sponge.

 

[PurplePolyp]

Doesn't to me.

 

[Gregcoyote]

How does this picture not look like that one, the green cast? These sponges come in a hundred different varieties. Why they are difficult to single out.
What do you think it is? I had a outbreak of them several years ago and they varied from white, to yellow, to green.

They generally start out white, but can change their cast. When you googled photos, you just picked out the white ones.