help! Id this thing spawning in my tank

[Afishianado]

I had my tank empty for the last year following a move and I got it back up and running over the last several days. I put in some new live rock 3 days ago but didn't get my lights on until tonight. Most of the rock is Fiji and there is a little bit of Kaelini in there too. On the largest pice of fiji rock I saw this worm thing crawl out of a hole. It was not quite as big as a standard pencil in diameter and poked out about 1 inch. It was black and white speckled, much like a scooter blenny but resembled a large bristle/fireworm to some extent although with much fewer spikes. Almost as soon as I saw it, it contracted then released a large puff of tiny green spheres (eggs?) then disappeared intot he rock again. a few minutes later another poked out from the other side of the rock ( maybe 8 inches away) and perfromed similarly except that it was spurting out white clouds (sperm?) and continued to do so for about 10 minutes then it also disappeared. I don't know what it was and was hoping someone could say if it is a good guy or bad guy for the tank. PICTURES ARE IN MY GALLERY, PLEASE CHECK THEM OUT, I did manage to take a small avi of it in action but I do not how to post an avi somewhere that people can veiw it. any ideas on how to do this?

[gwrulzmylife]

those sure are interesting. I've had thing "spurt" before from new rocks, clicking and clacking from rocks I've moved, been bitten by a mantis shrimp (I loathe them now!), and generally startled by the amount of life that lives in a single piece of rock.

[Putawaywet]

Well, for lack of actually seeing it about all I can say is that I know that's a pretty common occurance with rock burrowing organisms. When they decide to expell the leftovers they do so with a little puff of white smoke-like stuff out of their hole.

Brett

[Afishianado]

I have some of those things that scavange stuff then expell the left overs as well. These things are definitely not doing that. This this would pop out of the rock, then contract its body, then pump and expell this pure white cloud. It did this about 15 times over a 10 minute period. Also, the first one behaved similarly but instead expelled a large number of tiny green spheres, looked kind of like golden pearls( coral food) if you have ever seen those before.

The pictures are in my gallery on the left side of the image.

anyone else with some info?

[bmcelhinn]

How did the mantis tank feel? Ouch! I've always worried about that. Especially the nick name "Thumb splitters"

[brekke]

IMHO it looks like some type of bristle worm. I have the black/red ones myself tho. The spawning usually seems to occur with a high velocity wave motion (ie.. me with my fish net haha). The sperm is a white puff while the eggs in my case are pink goop that just sits on the rocks after the worm retracts.
Gotta say, it's pretty interesting to see and from a girl's point of view totally hilarious!

[nia]

Weird looking thing for sure. I'll have to go check in the Delbeeks.
I've seen the pink bristle worms do that in my tank. They just stick up their rear & spew(at least I think it's the rear LOL)

[Afishianado]

FWIW I have verified that this is a scale worm. If you do a search here on RC there are some pretty good pictures. Mine came out on the rock long enough to id with a flashlight the other night, of course the camera was not handy.

[nia]

Is it harmful or not? I looked thru my Sprung & Delbeeks, but didn't see anything that sounded like it. I'm getting confused as to what's good or bad for the reef these days. Used to be said that bristle worms were harmful, now in the latest Marine Fish and Reef annual there's an article about how most of them are more beneficial than harmful. In the article "Battling Dangerous Live Rock Hitchhikers", the author mentions a worm of gigantic proportions that he regarded almost as a pet! Yikes! The annelids with the pinchers are still regarded as evil, as they will catch fish. Wish I could get a pic of the latest thing I've spotted, but it's awfully tiny & hides very well. About a week ago a friend gave me a colony of Acropora that wasn't doing so well. It continued going downhill at an amazing rate. Last night I spotted a teensy little pink pincher waving about. Took me awhile, but I finally saw the critter. It's a very tiny crab. I don't know if it's the culprit or not of the coral's demise, but it is definitely it's residence. I once had a pretty lime green tree coral that had mysterious chunks taken out of it every morning. The problem was a small very beautiful lime green nudibranch who considered it bed & board!

[teevee]

All in context really, whether something is "good" or "bad".

I occasionally see small clouds of detritus being spat out of my rocks, almost like a geyser. I'd really like to know what dwells deep within the black rock (wasn't there something like that on LOTR?).