ID please

[bignose]

Something is definitely in there it comes out and looks like a snail.

[marie]

It's a vermetid snail, they are harmless but corals can find them annoying. A bit of epoxy sealing up the tube should do the trick

[MrGoodbytes]

+1

Seal it in there and the coral will eventually enrust it.

[bignose]

thanks I'll seal that thing up

[chris88]

i find they do no harm what so ever to the corals and do a decent job filter feeding out dertrius. They even increase coral growth because the coral will incrust down the length of the tube as the worm grows. Give it a chance before you kill it off.

[bignose]

Will these snails spread around my tank?

[Madreefer]

I had one living on the side of a clam. The "spider web" ended up getting bigger as time went on. Broke up the hard cacoon that it forms and picked the worm part out and disposed of it. Hated seeing that ugly web. Harmless but ugly.