odd thing on my live rock?

Question

I've this worm like thing growing on my live rock, kind of hard "exoskeleton" but can be crushed and always grows on a ring or circle...can you help me learn what this is?

Answer 1

Sounds like a featherworm from the family Spirorbidae - see photo at center to compare: http://www.nano-reef.com/gallery/showphoto.php?photo=6883

It could also be something from the family Sabellidae, but these have tubes that are less tightly spiralled:
http://seagrant.gso.uri.edu/research/georges_bank/Images/Species%20picts/Used/Protula%20tubularia%20large.jpg

These are harmless, but reproduce quickly and will quickly spread throughout your rock, not to mention the front of your tank, filter, etc. - they can be scraped off with a razor to remove them from where you don't want them.

Answer 2

It could be a tube worm, however I can think of a number of creatures including hard corals that could be growing.

Coralline algae will also grow, however they usually do not have worms growing from them.

this is the nice thing about live rock. You never know what you are going to get.

check out this site to see if you can find a picture that looks like what you have.

www.reefs.org/library/talklog/c_hofman_110997.html

Answer 3

Tube worms are a benificial invertibrte to have in your tank. There are almost always some on the live rock. You will find everything from diffrent types of worms, polyps, algae, starfish, snails and a ton of other stuff in your live rock. Its one of the reasons its called 'live' rock. Most of these things are great for your tank. Sometimes youcan get some things like flatworms which arent good but it is not as common if you buy from reputable sources. Good Luck!

Answer 4

Tube worms.
Good things to have.
You are going to find A LOT of other critters in those rocks too.