Can anyone ID this oddity? Thanks ;)

[sheria]

Hi there,
I ordered this "starburst polyp" coral some time ago. It seems to be doing well, however - I cannot seem to figure out what exactly the tube is extruding from the coral (or rather, the tube extruding from the rock that the coral is attached to).

On the bottom of the rock, its clearly sliced. In the center of the rock, you can see how the tube is "grown" into the rock, almost like the rings of a cut tree trunk.

There has been something in the end of this tube since the beginning. To best describe it, it almost looks like a black/brown "contact lens" - caving inwards.

I have a video to show it moving, but I'll post the pics first. Whatever is inside there, seems to have some type of antenna that pops around the spot in the center, and the entirety of it will move in and out, back and forth inside the tube - but only millimeters at at time. It is constantly excreting some residue also.

Thank you all!

 

[SeaCucumberFan]

1. Don't buy starburst, they will eventually take over the tank and choke your corals
2. That oddity looks like an odd rock formation. Is there anything inside it?

 

[AlSimmons]

Vermetid snail.

http://www.reefkeeping.com/issues/2005-01/rs/index.php

 

[SeaCucumberFan]

I nnever knew they grow that big

 

[sheria]

I'll be darned. You are exactly right. I'd have to say its around 1" in diameter. I'd have never figured that one out.

Also, thanks so much for the info on the starburst! I started with a very small Xenia a few months ago and it is now the size of a basketball. I may have to return the starburst.

Thanks again.