Anyone know what this is?

[75oceanic86]

This yellow "stuff" has been growing pretty rapidly along a live rock I purchased several days ago. It doesn't grow in any pattern as you cna tell, however it originally was a circular, yellow mound on the edge of the rock.

<img src="http://img.photobucket.com/albums/v340/Enthrodrakken/Picture240.jpg">

<img src="http://img.photobucket.com/albums/v340/Enthrodrakken/Picture248.jpg">

Any help in the matter is greatly appreciated.

 

[bertoni]

I don't know. Might be a sponge. You could try in the invertebrate forum.

 

[Gobie]

It could be a yellow sponge.

 

[DJM32189]

kind of looks like parts of yellow polyps that are going to form?

 

[75oceanic86]

<img src="http://img.photobucket.com/albums/v340/Enthrodrakken/Picture250.jpg">

As you can see, in less than two hours the yellow "stuff" has disappeared into the rock. More than likely it'll come back out of the rock soon.

It comes and goes as it pleases.

 

[lossman]

Yellow encrusting sponge. I have the yellow, orange and red forms in our tank. I get the dark navy blue type now and then, but the hermits love that one and devour it as soon as they notice it.

 

[75oceanic86]

Thanks a bunch for the classification! It's really appreciated, I wasn't sure if it was good or bad for the tank.

 

[oyam123]

"good stuff":rollface: