Can anyone identify what this is?

[ScubaGirl]

Here's a few more pics of the same thing. FINALLY had success with googling the camera macro online and got some tips. I wanted to ask about the little "grove" in the middle of the larger one too. The original pic didn't show it well at all but these ones do. Anyone know what they are? Another type of tube worm?









And then there is this yellow "stuff". We are getting more and more of it. Should we be concerned? Been googling with no luck on it either.





These are a little cluster of our tube worms. We already know what they are but I took a pic just because I finally had the camera settings figured out. We like 'em.