Bristle worm ID

[nano_reefer2010]

Any idea what kind this is? <a href="http://s1218.photobucket.com/albums/dd401/keifercooley/?action=view&current=7b2c8bfe.mp4" target="_blank"><img src="http://i1218.photobucket.com/albums/dd401/keifercooley/7b2c8bfe.mp4" border="0" alt="Photobucket Pictures, Images and Photos" /></a>
Thanks!

[Mike_Noren]

Yes, it's the most common (and beneficial) bristleworm in reef tanks, usually identified as Eurythoe complanata but in reality probably is a species of Pareurythoe. While it's a harmless scavenger it is also a member of the fireworm group, meaning it can deliver painful stings if handled.

For everyone you see you probably have a dozen you don't see; they can be ridiculously numerous in reef tanks, depending on food availability and predators.

[nano_reefer2010]

Thanks for the ID. Upon researching, they get 6"-7". That will be monstrous in a tank my size. Any idea on predators for an 18 gallon tank? I really have just a clean up crew in now so no delicate specimens to worry with at the moment.

[Mike_Noren]

Thanks for the ID. Upon researching, they get 6"-7".
The real Eurythoe complanata gets that big, but I don't think your worm will get bigger than 2-3".

[nano_reefer2010]

Thanks. Do you know of any thread, website, or anything else that has a comprehensive ID for these? I would like to identify this as accurately as possible to study under a microscope and share the images in my bio class.

[Mike_Noren]

No, sorry, I do not know of any resources like that. Identifying small & not-commercially-important marine invertebrates to species level is pretty much always a job for an expert.