New Live Rock - Green Spider Web ID

[Colonel]

I just purchased some cured LR from my LFS today. I run a FO and decided to add live rock over the next few months - about 10 lbs at a time to prevent any sort of spike to my FO tank.

This being the first night so I went and looked at the rock after lighs out. There was this green web on the rock. When I shined the light on it it started to retract into the rock. The end of the thread had two leaf like parts. The web like tread was over 8 inches long when extended. Later it was extended over the sand and the head was moving.

Any ideas what this is?

 

[horge]

Hi,

Look for online pics of Terrebellid worms with their feeding tentacles extended. Such tentacles end in a "T" of sorts. See if the pics you find match what you saw.

These scavengers can stretch their numerous tentacles over surprising distances, live in buried tubes constucted of mucus and debris, and are considered a very welcome inclusion in any reeftank.

They are known colloquially as Spaghetti worms.

horge