[rjs5134]

I guess I got the hang of posting pics... Anyone know what this is?? I have 2 or 3 in the tank that I know of. The largest is probably over 6" long. I'm not really sure I've ever seen them end to end though.
http://www.reefland.com/forum/attach...1&d=1140985147

[optical]

thats a big ol flippin bristle worm. their bad but only when they get big. that looks like a big one so you should try to set a bristle worm trap to catch him. if you see it, you might be able to take a pair of tweesers and grab it that way. some of them can sting pretty bad so i wouldnt advise you to touch it. some species will reek havoc on your corals and can even eat sleeping fish! their hitch hikers from your rocks.

[greenbean36191]

Harmless species are harmless regardless of their size. There isn't any reason to get rid of this worm. It won't hurt anything.

The worms that can cause big damage are in an entirely different family.

[optical]

greenbean, i know some bristleworms arent really bad, but how can you tell which ones are? i had one that i saw crawling out of a rock hole so i grabbed it and it seriously stung my fingers. it felt like a burn-for about an hour. i also saw one eating at a button polyp before- it was about 2 inches long. they both looked like the same species, which looked very similar to the one in that pic.

[Ninong]

Originally Posted by rjs5134

Anyone know what this is?? I have 2 or 3 in the tank that I know of. The largest is probably over 6" long.

It's a beneficial detritivore. They're great scavengers. Congratulations!

If you see two or three, you problably have at least a couple dozen more. Just check your tank a couple of hours after the lights go off at night. Use a red flashlight or place red cellophane over the lens of a regular flashlight. Using a regular white flashlight will help you see them for a couple of seconds but they will go into hiding immediately when the light hits them.

The one in your picture looks like it could be in the genus Eurythoe, possibly E. complanata.

Here's a picture of one of mine. This one was 7" long when I took his picture.

http://www.reefland.com/forum/attach...g?d=1135809655

[greenbean36191]

greenbean, i know some bristleworms arent really bad, but how can you tell which ones are?

You have to know your worms. This is obviously a fireworm judging by the prominent calcium bristles. Only one of the fireworms in the hobby, Hermodice carunculata is a predator. The bristle arrangement and body shape of this one aren't characteristic of that species. Plus that species is pretty rare in the hobby anyway since it comes from the Caribbean. To actually say 100% that this is a harmless species would take a clear shot of the head, but without it I'm about 90% sure.

The other predatory worms are in different families, mainly Eunicidae, and lack the prominent stiff bristles.

[CSeaSee]

Here's a pic of a predatory one... definately not yours.
Attachment 7022

(Edit added by moderator: That's a picture of Hermodice carunculata.)

[optical]

haha, i definetly do not know my worms. i'll get a pic of one of those worms in my tank when i spot it. maybe you can id it.
--sneek attack shot! i just hope that the camera flash wont reflect too much in a dark tank.

[BubbaWPB]

Originally Posted by optical

i just hope that the camera flash wont reflect too much in a dark tank.

Just make sure to take the picture at an acute angle to the glass - about 45 to 60 degrees, and make sure that if your camera has a "red eye" feature, that it is turned off.

[Ninong]

Or place the camera's lens flush against the glass wall of the tank to avoid flash reflection.

P.S. -- The picture of mine was taken in the daytime but I believe just the actinic fluorescents were on at the time and I probably used a flash. I really don't remember. Anyway, mine used to sneak out from beneath the live rock and go as far as four or five inches onto the open sand bed to retrieve sinking pellets that I fed for my Nassarius vibex snails. I had too many Nassarius vibex for the size of my tank and I had to target feed them to keep them going. The larger bristleworms would take food away from the snails without a problem. The most amazing sight was watching some of the snails actually crawl over a bristleworm's body without any apparent problems with the bristles.