Is this a Coral?

[fish addict]

I have this growing on a rock in my tank. It is chalky/ white, with an X like opening, and it seems to be spreading a slimey substance. Is it a coral or barnacle, or what?



look in the center of the picture

 

[OrionGirl]

Anyway to get a bigger picture, or more light?

There are a number of possibilities-sponges, corals, worms, etc. Have you touched it?

 

[fish addict]

Aha! I think that I got the picture thing right this time! The original image should be much larger now. Still not a great shot, but you should be able make out the X shape in the circle. It is spreading a bluish/white ooze around it.

The "growth" appears to be fairly stoney/ hard; it opens and closes some.

 

[RENEGADE]

looks like one of the robots in DECENT

 

[mogurnda]

If I squint, and use a little imagination it looks kind of like the channels in an encrusting sponge.

 

[ragc]

Could it be a vermatid? The head-on view of the head when inside it's tube is similar, and they secrete their web and then suck it in...

 

[mysis]

Possibly