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Bristle/Fireworms, Polychaete Behavior FAQs 

Related FAQs: Worm Behavior, & Bristle/Fireworms 1, Bristle/Fireworms 2Bristle/Fireworms 3, Bristle/Fireworms 4, Worm IdentificationPolychaete Identification, Polychaete Compatibility, Polychaete System, Polychaete Selection, Polychaete Feeding, Polychaete Disease, Polychaete Reproduction

Related Articles: Worms, Polychaetes, Flatworms/Planaria

To Bob Fenner... A bioluminescent Eunicid!         8/4/15
Hello Mr. Fenner,
<Hey Vic!>
I´ve read this thread recently:
<Really neat; and big>
... and I´m writing you because I´ve been able to record the bioluminescence of an *Eunice sp.* worm.
Here´s the link to the video: https://youtu.be/lbkU2DIXiwU
<I see this... and... it appears voluntary... >
It´s a pity because when it was in the aquarium, the light was so powerful that it seemed some kind of electric powered device. It even released a luminescent mucous.
Regards from Spain,
V. Tovar
<Thank you for sharing. Bob Fenner>

How do bristleworms attack? 3/29/13
Hi there
I've been 'attacked' by a Bristleworm in my tank.  I was moving rock and corals between tanks with gloves on this morning and saw one more rock I could grab and was too lazy to put the gloves back on.  It hurt a bit when it happened but it's OK now as long as I don't play with the hairs.  I thought I'd show my kids and they freaked out thinking I was contagious!   After they calmed down a bit my son had a good look then asked if they shoot out the hairs or do they actively stab you?
<More the latter... not active, but your mechanical contact and pulling brought out these>
 I had no idea!  So whilst I'm waiting for PVA glue to dry I thought I'd ask the question here… How *do* they attack?  Do they see you coming and aim for you or do you actively have to jam your fingers on them? 
<Mmm, there may be some positioning, but most all encounters I've had were passive on the worms' parts>
One more question…Am I a real reefer now I've been electrocuted (mildly), stabbed by a urchin, spent all my money, been bitten by a clown fish, flooded the house and stung by a Bristleworm?
 Or do I need to be cut by my tang first?
<I'd say you're part of the club already!>
Thanks heaps!
Camille :)
<Thank you for sharing. Bob Fenner>

Eunice worm question, ID, bioluminescent beh.    4/12/11
Hey Crew!
Quick question regarding a Eunice worm I found in my Nano tank. I'm looking for a specific (as possible) ID so I can accurately match up a threat level that this creature poses.
<... Ok>
I am not able to snap a photo but there are a couple characteristics that may narrow it down.
The color on the worm's plated back is primarily dark brown/black with a hint of metallic red that really shines with a flash light. That in it's self is neat, but the cool part is that when you harass the little bugger, his head flashes blue. The flash holds for a full second then fades away.
I tapped him with a spoon two nights ago and he "flashed me" in a quick retreat. I then tapped the hole that he was burrowed into and the entire hole glowed for the same amount of time. The blue is very similar to a blue actinic 453nm LED. It's pretty awesome. I'll NEVER be able to catch a still shot of that, but I will definitely try to video the blue flash..
<... there are about 200 species of Eunicids. Do search on WWM (we've ID'd a few) and the Net in general... and/or college level invertebrate zoology texts>
The tank is a 14g Biocube with ~15 pound of live rock (origin is The Coral Sea if that further narrows down the possibilities).
I am on the fence. Anyone that has read up on Eunice Worms know the potential terror that they can cause. This tank will host primarily corals. I have about 4 or 5 prominent colonies of Zoos, some GSP, 6 colonies of Acan, and some other random mushrooms that I am basically growing to trade. None of these have been touched in the 4 months that the tank has been running. There's one clown and the average cleanup crew.
I've lost one snail, but again, that's not necessarily uncommon. I barely feed the tank so I imagine the thing would be getting hungry and attack the corals if desperate by now.........
<Some Eunicids do eat coral...>
Any thoughts on an ID or potential risk?
<I'd remove it/them if they're of size, such concern to you>
Thanks everyone!
<Welcome. Bob Fenner>
re: Eunice worm question   4/12/11
Thanks Bob! I appreciate the response!
<Welcome Robert>
I have searched high and low for information and I'm not finding a lot of reputable info on bioluminescent Eunicid..... is that flash of blue a common defensive feature across the line of Eunice worms or is this a unique characteristic?
<Mmm, not especially... Could well be bioluminescent bacteria in the water or on the worm's exterior>
Also, do you know of any specific university studies that are the "end all" on Eunicid? I'd love to look it up and maybe pick their brain on the subject.
<Heeee! I "spent" a few years as a college student "sorting and identifying Errantiate Polychaetes" for bioassays... but that was decades ago. Am sure that a cursory search (BIOSIS, the Zoological Abstracts) perhaps w/ the help of a reference librarian... at a college with a bio./zoo. dept., will show if there is such a tome/study. B>
re: Eunice worm question    4/13/11
Thanks for the direction..... I'm in NC a little ways east of Raleigh.
<Ahh, have visited there>
I know of at least one marine biology offshoot in Morehead City (it's either Duke or UNC, I don't remember). Maybe I'll look them up and see if anyone can spot me a lead.
<Real good>
Question regarding the bioluminescence. The blue flash was very isolated on one particular region of the worm's head and it only flashed in response to my physical threats via long handled spoon. If it were bacteria in the water or externally on the worm, is the worm acting in a certain manner or doing something to trigger the flash response (assuming the flash could be bacteria)?
<Can/could be triggered... most folks think by movement alone. Am not so sure>
Perhaps some sort of symbiotic trade? Has a relationship like this ever been noted or is it more on the lines of theory?
<Either not so theoretical or yet another instance of my faulty recall>
I don't know why I am fascinated / dragging on this conversation about a worm.... but nonetheless, I appreciate your insight/website/and thoughts on the subject!
I'll bet this won't be the end ;)
<I do hope not>
Till next time
Re: : Eunice worm question. LynnZ chimes in    4/13/11
Hi Bob,
<Hey Lynn>
Sorry, I saw this query earlier but was not able to answer it the way I wanted.
I was on the way to yet another doctor appointment! Anyway, I don't know about Eunice worms and blue emanations, but I have read of bioluminescence in Chaetopterus spp./family Chaetopteridae worms, Scale worms/family Polynoidae, and some Syllids/family Syllidae. Chaetopterids in particular have been reported to release a luminescent mucus, when threatened, that results in a bluish light. Unfortunately, I don't have any links to list right offhand, but an internet search should prove fruitful for Jon. Hope that helps!
Take care,
<Thank you Lynn. Have cc'd JonH here. BobF>
Follow-up Re: Eunice worm question -- 4/14/11

<Hi Jon, Lynn here today, sticking my nose into this worm situation again!>
Well, I have some research to do!
<Yes indeed! The good news is that at least I can offer a few links today to help you on the way.>
Right when I feel I have exhausted every search query possible with every synonym or scientific name I can find, someone uses "emanation" and "Chaetopteridae" in a sentence and I realize I've barely busted the surface. It's about to get nasty.
<Heheee! I know the feeling well! Try 'Polychaete + bioluminescent' or 'Polychaete + luminous'. Once you have a list of potential candidates, explore each and narrow the possibilities. I've done a bit of research but haven't been able to connect Eunicids with any sort of blue light. I've only found it associated with Chaetopterids. That doesn't mean it's not possible. It could be that it's buried somewhere in a book or else it's in a study that's not available online to the public. It's also possible that it just hasn't been discovered, or formally studied and presented yet. Beyond that, it's possible that what you have isn't a Eunicid at all, but something else entirely. By the way, of note is that the Syllids I know that release luminous secretions, do it while spawning. I don't know if they're also capable of releasing any glowing substances when threatened.>
Ok....... maybe I am going about this in the wrong fashion and I'd like to exhaust another avenue. It is very likely that I am mis-identifying this creature.
<It's very possible. It surprised me yesterday when you said that you were able to tap the worm with a spoon. Typically, you'd never get that close to a Eunicid without trapping it first. They're pretty fast when it comes to erupting from, or disappearing into, their 'homes' (burrows, tubes, crevices, etc.).>
Again, no photo makes this a bit of a goat rodeo..... a photo could simplify the process immediately....
<Hopefully it would allow us to at least narrow the list of possibilities.>
..nonetheless, are there any type of worms (common or scientific name) that you could see as easily being mis-identified as a Eunice?
<If the ID is based on multiple antennae and a roundish body, then there are many possibilities, including Syllids, Phyllodocids, Nereids, etc., etc. Those are just the ones that occur to me offhand. I'm not even going to try to pretend to know all of the other possibilities! Your best bet is to explore several good ID sites, like Bob's page (http://www.wetwebmedia.com/polychaetes.htm ), as well as that of a friend of mine's (Chuck's Addiction): http://www.chucksaddiction.com/hitchworms.html .
Try to narrow the possibilities and go from there. If that proves unfruitful and you really want to dive headlong into the ID, please try the following site. It's a Polychaete Family Identification Key with some fairly complex terms but each has a link with drawings and a description/explanation: http://www.nhm.ac.uk/research-curation/research/projects/taxinfo/key/family_key.htm
This terrific site also has a handy "Family Browser" section located here: http://www.nhm.ac.uk/research-curation/research/projects/taxinfo/browse/family/family_browser.htm >
It's round-ish, less than a 1/4 inch thick, plated,
<When I hear this term, I picture a scale worm (Polynoid) because they look like they're plated with scales. Their body, however, tends to be more flattened than round.>
..millipede like, 5 tentacles or so
<Chaetopterus spp. are tube-dwellers with two grooved feeding tentacles ('palps') and that's it. They're also filter-feeders, not scavengers.>
..(no pinchers like the classic "bobbit" videos on YouTube),
<Heheee! Yep, those videos are enough to keep a person awake at night! Interestingly enough, I've had Eunice worms in my tanks for years and never had any problems. They do a bit of scavenging and probably grab a pod, or other worm, here and there but that's it. I've also never seen any jaws. They stay tucked inside the mouth until ready for use.>
..and has a red metallic hue......
Thank you so much Bob! You and your network of information providers continue to serve me and the community well! I am very grateful and I'll continue to preach the gospel of WWM!
(PS, the worm made another appearance last night but did not venture far from his dwelling.
<That's typical of the Eunice worms I've had as well.>
An interesting observation.... he is clearly using a network of passageways in said rock and seem to use 2 exits primarily for his scavenging. The "main" exit (used most) had the arms of a micro brittle in it for the day yesterday, into the night and still this morning. There was no struggle or anything and the star appeared to simply be doing what brittles do.... sit there and flap their arms in the current.
<Yep, that's typical.>
During my observation during lights-out, I watched a star go in the hole that housed the worm, hang out, and literally brush up against the worm as he bobbed his head in and out.
<Neat. I've seen one in a crevice with a Bristleworm but that's it.>
I can't jump to any conclusions based on that, but the lack of aggression from the worm has been minorly reassuring.
<Yep, apparently the worm doesn't have a taste for Brittlestars at least.>
I think I can get a dim light on the rock tonight or tomorrow and capture some video and still shots.
<I'd love to see it/them.>
If I can grab any documentation I'll be sure to share)
<Excellent! I look forward to it!>
Thanks again Bob! WWM is my go to source on fact, theory, and everything else involved with aquaria! I appreciate everything!
<On behalf of the two of us, you're very welcome Jon, and thank you! Take care, Lynn Z>
Re: : Eunice worm question 4/14/11
Lynn (and Bob)
Wow! Awesome, awesome stuff!
I've spent a lot of time reading. Who knew worms could be so fascinating?!
<Oh yes>
Ok.... it's late and I'll cut to the chase. I have video :)
Here on YouTube
As of 12:31 am Eastern the YouTube site is still "processing"..... I'm not sure if it is 100% live and ready. I probably looked like an idiot while filming..... I'm right handed and used my left hand to film.... it's shaky at times and the auto feature takes over in spots, so bear with me..... it also takes me a second to master my coordination with the left hand, but trust me, there are some extended shots with a clear picture.
There is a micro bristle near the worm so you can have a size reference.
In a second video I tried to harass him a bit with a butter knife (I don't plan on uploading it because for the most part it doesn't show a ton more than what I am describing here). I cut the flash light off and was able to get a blue response, but he was in his hole. He actually extended a bit towards the knife as I approached him as if to check it out. While doing this is exposed a very "white" underside..... I think this may be where the bioluminescence is coming from...... based on his actions I think I can get this on video on another night....... I kind of scared the crap out of him while knocking on his hole and he hasn't come back for about 10 minutes..........
Ok, off to bed.... if I missed details I apologize..... must sleep.........
<We'll have to wait for the link/ref. BobF>
Re: : Eunice worm question 4/14/11
Hey Bob,
I thought I hyperlinked the "Here". &nbsp;If that doesn't work I'll email you when I get back to a desktop.
<Mmm, no link. B>
Re: : Eunice worm question -- 4/14/11

There's a part where the worm shows a little curiosity to the neighboring starfish..... the starfish responds with a "love tap" just after the 2:20 mark
<Interesante. BobF>
Re: : Eunice worm question -- 4/14/11
You're killing me Bob! Your virtual screams show no signs of reassurance ;)
Eunicid or not? The more I look at it &amp; compare with photos, the more I'm convinced that it is a Eunice. I also will humbly declare my amateur status and leave the final decision to you and Lynn.
<This could well be a Eunicid>
The worm showed a lot of curiosity towards a butter knife last night. I found the tripod for my camera. I'm going to lure him out and spook him a bit to catch that blue flash on video. It's really cool.
Type with you soon
<Little doubt. B>
Re: Eunice worm question -- 4/14/11
<Hi there, Lynn here again.>
<Neat! That critter has Eunice worm written all over it. You can see the similarities here: http://www.nhm.ac.uk/research-curation/research/projects/taxinfo/browse/family/eunicidae.htm >
There's a part where the worm shows a little curiosity to the neighboring starfish..... the starfish responds with a "love tap" just after the 2:20 mark
<Yep, I couldn't help but snicker when I saw that. I guess the Brittlestar had finally had enough!>
<You're welcome and thank you for the terrific video! Take care, Lynn Z
Re: : Eunice worm question -- 4/15/11
Ok..... hypothetical question. This worm has a fairly developed head (for a worm anyway). If The Queen of Hearts declared "Off with his head!", would the remaining body have the ability to regenerate that complex of a structure or will the injury kill the body? From what I've read there is actually a lot of neuro activity going on at the front end of a Eunicid and I question the regenerative capability.
<Mmm, anterior losses of size, other than tentacles... are more problematic than losses further back>
I will continue to try and capture this guy via humane efforts. I've found someone with a dedicated Eunicid tank in Raleigh so I know I can give him a home..... and if it's not killing any wanted livestock I'm really not concerned with his presence. But, if this thing gets creative with his diet and push comes to shove, well, I'll have to have a talk with the Queen....and we all know her favorite line......
<Usually quite easy to bait/trap... all gone over on WWM. B>

Constructive worm 4/7/2011
<Hi there Carissa>
I have some kind of unusual worm that I can't find a similar description anywhere! I've only seen its head once for a few seconds just before turning off the lights as it appeared to be grazing on some algae-- a kind of grasshopper like head with short antennae. He seems sizable, the head was about 3/8 inch wide. So he could be a Bristleworm,
<Very likely so>
but this worm seems to have a talent of moving small rocks and attaching them to the rock he lives in (see attached picture-- his home rock is like a piece of Swiss cheese, so I can't find him during the day). The white rocks on the left side were brought up about 5 inches from the bottom of the aquarium just last night, and as a reference for size, the one at the front is about 3/4 inch long! They are very light weight aragonite, but I'm still thinking, how big is this worm to bring up these pieces of gravel?
<Good sized, strong>
Then the rocks are connected to the 'home rock' with strands of silk-like substance (seen in the middle section just under the red macro algae). And the pieces at the right are attached and hanging from the rock. The rocks aren't in any particular tube shape, either; just placed in-between the two rocks.
<A good clue. Perhaps this is a Eunicid... see the Net re>
I'm not too concerned about the worm harming anything else in the tank.
I'm just wondering what it is and if it will grow into a giant. I've had my tank for 2 months and the live rock with the worm for about a month.
Specs: 26 gallon saltwater, canister filter, skimmer, 76 degrees, ph 8.3, ammonia 0, nitrite 0, nitrate <5ppm, 2 green Chromis, 1 Firefish goby, frag of brown Zoas.
Thanks for any help!
<Could be trouble for the Firefish if this worm is hungry. Bob Fenner>

worm head?

Bristleworm eating substrate   2/1/11
Hello! I've taken the plunge and bought an already established 58 gallon reef tank a little over 2 weeks ago - nitrates were a little high temporarily but everything seems to be amazingly fine despite a mid-winter move.
<Ah good>
I noticed a Bristleworm (one of several) this morning, about 1/8 inch wide and 2-3 inches poking out of his crevice. He slithered partway out, sifted through the substrate, grabbed a chunk with a wide open mouth, and took it back to his hole. It's CaribSea Special Grade Reef Sand to give you an idea of size. I returned to the tank a number of times throughout the day and could always count on seeing him doing this. At one point I noticed he was swallowing 2 or 3 pieces before taking a chunk back to his hole. He was actively "eating" all day long. It was like watching a python devour prey.
I could see the substrate inside him. I haven't been able to find any information on why a worm would behave this way.
<Interesting. I too have not seen, nor read reports of such ingesting>
There are numerous hitchhikers, a couple of hermits, a couple of urchins (one too many in my opinion) and several snails - plenty to eat without having to resort to the substrate! Have you ever seen such behavior?
<I have not>
The substrate looked "clean" - we mixed in about 20 pounds of new sand to the existing sand when we set the tank back up. It's about 2 inches deep for what it's worth.
Thanks for your time! WetWebMedia has satisfied my curiosity countless times - including today when I discovered I had a few survivors (Galaxea) of what I thought was a dead coral skeleton!
Have a great day!
<Will do, and thank you for reporting your observation. I suspect this (gravel) "too shall pass". Cheers, Bob Fenner>
Re: Bristleworm eating substrate 2/3/11

Thanks so much! I've since determined that it's a type of Eunicid (and he has at least one good-size friend I've also spotted). The live rock was from Tampa Bay Saltwater and I've heard that they are not uncommon finds in their rock.
<This is so>
A trap hasn't worked - I'll remove the rock and flush them with seltzer. I believe what I witnessed was the worm building a den as sometimes he just picks up rock and "arranges" it around the entrance, but I'm still puzzled as to why he would swallow it.
<Maybe to "coat" it with material for fastening into a tube>
Maybe it's easier to carry that way! I'm sure it won't be the last unexplained thing I witness in the tank - may as well sit back and enjoy. Thanks again, and have a great day!
<Thank you. BobF>

Bristle worms spewing 08/12/09
I have a 33 gal tank. Moved a few rocks around tonight and noticed a giant bristle worm (pinkish-peach) expelling something pink into the water. Then seconds later another... Then another... and even more still, including a feathery looking one that was caterpillar like !? What the heck? Is it toxic? And I have some giant worms... Should I be plucking these critters out?
<They are likely spawning. No need to remove them. This is a good thing (usually).
Sara M.>

Relationship between hermit and spaghetti worm 4/29/09
Hello all!
Is it common or well-known for a spaghetti worm to "host" or form some kind of symbiotic relationship with a hermit crab? I have a Mexican red-leg hermit using a Cerith snail shell with a small hole bored in it (I assume made by the predator which killed the original snail). There are two long tentacles coming out of the hole that to me look identical to a spaghetti worm. They wriggle about and withdraw just as you'd expect them to. Have you seen this before?
<Hello Emily. It's actually pretty common for Hermit crabs to form symbioses of various types with a number of different animals. One of the European species, Pagurus bernhardus, has been quite well studied in this regard. It routinely forms a symbiosis with sea anemones (several species) that it actually moves from old shells to new shells as it grows. Inside the shell there is a Polychaete worm, Nereis fucata. The crab and the anemone are assumed to benefit one another, the anemone by being moved about and perhaps collecting food from the crab, and the crab gets the benefit of the anemone's sting. As for the worm, there's no particular benefit to the crab, but the worm certainly snatches crumbs of food and lives somewhere relatively secure, defended by both the crab and the anemone. As for worms living inside burrows through the shell, the hermit crab likely doesn't notice or care about these, any more than you do the thousands of mites living in your eyebrows. There's little to no interaction between the two of them, though perhaps the burrowing worms might benefit from crumbs of food that drift about when the hermit crab feeds. Those worms would be in that shell regardless of whether the shell was occupied by a snail, a hermit crab, or was just sitting about on the substrate. As such, it's not really a symbiosis _per se_. It's better to think of a symbiosis as a situation where animals make particular efforts to interact with one another, and when doing so, at least one partner benefits. Cheers, Neale.>

Re: Relationship between hermit and spaghetti worm
Thanks for the info, Neale!! I think it's kinda funny, this crab is hauling around a freeloader! Pretty neat :)
<Some 10% of your (dry) body weight is bacteria. On top of that, there are mites in your eyebrows, amoebas crawling around inside your mouth, yeasts on your skin, and more besides! The only thing unusual about the "freeloader" you're seeing on your Hermit is that it's visible; most aren't. Cheers, Neale.>

Feather duster lost head 01/16/09 I noticed I hadn't seen my Hawaiian feather duster show any display over the last two days, and today I found his head laying in the bottom in the corner of the aquarium. Do you think he's dead, or is this normal? <I think you mean that it has shed its crown (the feathery part). This is sometimes "normal"... but it could also be a sign of stress. If the worm is healthy, it will regrow its crown.> Thanks, Pat <De nada, Sara M.>

Feather duster cut in half? 01/16/09 Dear Crew, I have only had need to write WWM once since setting up my first saltwater tank two years ago. I am enormously thankful for the information here, read daily, and want to kick those who are intentionally ungrateful or rude to the staff of volunteers there. Thank you so much for your site, I have successfully stocked 3 tanks (lightly) with sick or dying corals from others, and all have regrown beautifully. <good to hear> Currently, I have a large feather duster that appears to be dying in my 60 gal LPS tank. (Tank houses much live rock, Chaeto, a small Tomini tang, algae blenny, and a falco Hawkfish, as well as a 'non aggressive' clean up crew. I change five to ten gallons with aged water twice a week [RODI], use an Aquaclear 110 for Polyfilter and ChemiPure, as well as a cheap skimmer modified which pulls an enormous amount of disgustingness out of our well fed water. Flow is provided by two Koralia 2s and an intermittent Koralia 3, and the lighting is power compact [320 watts]. I do not have a refugium or sump connected to this tank.) He has been in the tank for more than eighteen months, and has grown and behaved like your average feather duster (in a fabulous environment with plenty of food). However, his morning it was extended out of its tube by three inches. Within an hour or two, he crawled out, and to my surprise, appeared to be cut in half about three inches below the crown. The two ends of the 'cut' appeared relatively clean, but with one small piece of flesh holding them together. So, now I have a feather duster tube, with the lower end of the worm in it, and a free floating (and protected, for now) top half of a feather duster in my tank. I am inclined to remove the upper portion, but would hate to do so if it has even a slight chance. <No, no... just leave the worm alone. They sometimes do this. Just let it be.> My water parameters tested as they normally do (nitrates 0, pH 8.2, ammonia 0, calcium 410, dKH 11). I changed 15 gallons anyway, and everyone else in the tank appears to be happy and healthy. I have no idea how this could have happened, and while I have a few tiny hermits, as well as the normal population of bristle worms- I do not see how anything in my tank could have mechanically injured the feather duster. <It might likely not be mechanical. The worm might have done this to itself.> So, my questions for the Crew are these: 1) Is it possible that either 'end' of the feather duster can survive given the chance? <Yes> 2) Do feather dusters normally expose several inches of their bodies? <Not "normally"... but it does happen.> Or is there a predator in my tank capable of entering a feather duster worm's tube (tiny hermit, etc)? <I think something might have irritated it enough to want to "escape" its tube, possibly to move elsewhere. But I couldn't tell you what that irritate might be.> 3) Is it possible that this is a reproduction strategy? (While I queried this, I myself have never seen a large feather duster snip itself in two.) <This is possible.> I do all that I can for my tanks, which mainly consists of convincing myself to leave them be and not tinker, but I do not want to foul my tank or hurt this guy in any way. Any advice or thoughts would be much appreciated! <I would just leave it alone and see what happens.> You guys/gals are truly awesome. Thanks you so much. --Carolyn <Thanks and De nada, Sara M.>

Re: Feather duster cut in half? 01/16/09 Sara, Thanks so much for taking the time to answer, and so quickly! I suspected that I should leave him be, but I was too caught up in freaking out. <Hehe, I know the feeling!> The upper portion has buried itself alongside the rock which houses its original tube. <That's good! It might likely be rebuilding its tube as we speak.> I really hope both pieces survive. <Let us know if they do. :-)> Thank you to You, and the rest of Crew. --Carolyn <Cheers,
Sara M.>

Bristleworms... Observations... Reproduction and Removal   10/21/07 Hey Team: <Hi John, Mich here.> Not really a question today, just more of an observation. I was scraping my tank walls and creating quite the amount of wave action ;). During the process tons of red bristle worms came out and began hanging half way out of the rocks and then releasing a red (pinkish) fluid into the water <Possibly reproductive materials.> I am sure they do this all the time, however, it was the first time I had witness such occurrence. <Neat!> Also was a great opportunity to pick out some of the longer ones. <Thanks for sharing. Mich> John

Night of the Triffids... Polychaete repro. event  4/25/07  Tonight (April 24, 2007) before the lights went off watching my tank (200 gal, 7 years old) I saw something truly strange. Water started changing into milky colour, very quickly. Worms, light pink, between 1-2 ", looked like bristly (but I've a doubts - I use something similar for fishing) <Yes> sticking their heads from all over and spitting white sperm-like matter. <This and eggs> Didn't know so many in my tank. Hundreds of them! Bottom - No sand - shells only and rocks.   Fishes were bothered a little by the whole situation; corals and anemones not at all. During the day, when I vacuum tank's bottom, always get a good bunch of them. If that what happened is what I think it is - I'm in trouble: in the near future there will be infestation of these worms in my tank. One good thinks - they have to eat what is left on the bottom after snails, crabs and shrimps. After few hours water is still white cloudy.  What in the world what that? Night of the Triffids? I presume. Marcin Mankowski <Please read here: http://www.wetwebmedia.com/polychaebehfaqs.htm and the linked files above. Bob Fenner>

Bristleworm and Cat Shark Issues - 4/17/07 Hello. <Hi there!> We recently hatched a small banded cat-shark in our 90gallon tank. (Don't worry, when he grows he will be destined for a much larger 240gallon) <Mmmm, hopefully that will be soon as these sharks grow very quickly in their first year. I wouldn't have recommended anything smaller than a 125g to start - for the shark alone!> Last night I had the flashlight out watching him feed on ghost shrimp, as his appetite has been hit or miss in the first few weeks. <Not unusual in a very young shark. Am concerned though, about its well being in a crowded community tank. Sharks, especially just out of the case, are vulnerable and in need of some quiet and care. A situation such as this could be very stressful/detrimental. Please watch for aggression (picking/nipping) from other fish, along with any signs of decline.>   While doing this, I noticed a few large orange puffs appear in the tank. I watched, and found some large (~3inch) bristle worms would stick one end in the air and "discharge" a milky orange looking cloud. I managed to film one of them doing this. <Neat! By the way, thank you for sharing this experience with us. It helps us all!> Then I noticed several of the smaller ones doing it on a much smaller scale. The entire tank became as cloudy for a bit.  Now, my questions are 1) What were they doing? <Likely releasing gametes/spawning.> 2) Was it harmful to the tank? <No, just added to the nutrient load.> 3) Our population seems to have really exploded since our arrow head crab died. <Yes, rapid population increase likely due to a nutrient problem, combined with the loss of a predator. Decrease/export nutrients and the Bristleworm population will fall on its own, to more normal levels. Please see this link regarding nutrient control: http://www.wetwebmedia.com/nutrientcontrol.htm.> I am hesitant to get another, as we have a fire shrimp and a red striped shrimp that I am worried would be no match for an arrow head. <Given the chance, the shark will eat these first, then go after any slow fish you have (mandarin).>   What would you recommend as a population controller in our tank? <(See above) Unfortunately, your tank is more than overcrowded, which is putting a strain on your system's ability to process the bio load (and it's only going to get worse as the shark grows). It's also not an ideal situation for the inhabitants. Please read these links for more information on shark keeping and compatibility: http://www.wetwebmedia.com/sharkcompfaqs.htm http://www.wetwebmedia.com/sharkslvgrm.htm> FYI, in addition to the shrimp and cat-shark we have the following: 2 blue damsels, 2 silver damsels a coral beauty, and angel, a yellow tang, a large clown fish, and a mandarin goby. Todd Aston <Take care and good luck! -Lynn>

Re: Coco Worm with "heads"  that change color!   1/30/07 Here are some sequential pictures taken about 1 to 2 seconds apart. It did this for several weeks then sort of settled into the pink color until it shed it's "heads". After it grew a new pair of heads, the color switching began again and is still changing colors now. It is getting close to full size again so I don't know what's next! <Call the News Channels! Yes, I'm serious> The color changes are very easy to see any time of day under any lighting. We also have video documenting color change in real time. Don't know if we have the only one or they are common but I've never seen anything quite like it. Thanx! For your time Rick Oppermann
<Thank you for sharing. Bob Fenner>

Electric worm in my reef tank!   9/4/06 Dear Mr. Fenner, <Derek> This evening I decided to have a look in my reef tank while the lights were all out, in the hope I might see one of the many creatures that spend the day hidden in holes in the rocks. <Is really a fun, neat time for observation> Well, I saw my boxer shrimp behaving a bit odd, looking like he'd caught something, so I looked closer hoping it wasn't one of my fish. At first I couldn't see anything in his claws but he seemed to be wrestling with something. A moment later two thin strips of vivid electric blue lit up between his outstretched claws and he jumped back like he'd put a pincer in the mains socket. <Ah, yes, phosphorescence... not uncommon in the wild> I continued to watch, trying to adjust my eyes to the dark water, and again a flash of blue, the shrimp jumped back again. Eventually I could see he'd caught what looked like a 2.5" long worm. It was too dark to make out properly, and I didn't want to suddenly light the whole tank up, but the worm looked thin and flat, and while the boxer tried to eat it the worm shot lines of really bright electric blue along its body. <A type of reflex defensive mechanism> it looked like the shrimp was chewing on a live wire, but the most beautiful blue glow. The glow clearly hurt the shrimp, though he didn't give up, and at this moment the boxer appears to have won and is slowly eating the worm. Now that the glowing has stopped the worm looks very plain and could easily be a bristle worm, but do they glow like that? <Can, yes> Whatever this is it has me very excited, I'm amazed to see an unidentified glowing creature in my little reef. I almost wanted to stop the boxer killing it but short of pulling every rock out there was no way I'd separate them, and I also wondered if this worm could be a danger to the fish anyway. I'm a big fan of Wet Web Media and have spent many hours reading through your FAQ's, so when I saw this unexpected and unidentified creature I thought of contacting you first. Have you any idea what it was? <Yes... an instance of (observed) bio-phosphorescence...> Did I get all excited about something common? <Mmm, not commonly seen in captivity> I'm fairly new to reef keeping but to me this felt like some kind of discovery ;) I tried to get it on my digital video camera but it was too dark to see anything. I'd love to know your thoughts. I've tried looking for similar things online but turned up no clues at all. Thanks in advance for your time, and thanks for the great site. Regards, Derek <Do take a look/see on the Net with the term: "biological phosphorescence/luminescense in the sea" in your search tool/s. Bob Fenner> Re: Electric worm in my reef tank!   9/4/06 Dear Bob, <Derek> Many thanks for your reply. I feel very privileged to have seen this if it is not commonly observed in captivity. Now I'm trying to find out what the tiny star shaped white things are on my glass, they look sort of like tiny white starfish (in shape only) but with only 4 stubby 'legs'... they're maybe 5mm in diameter. <Mmm, likely Asterina sp.> I've only ever seen two in the tank (at one time). Any ideas would be very welcome...I'll continue my search on that. <Look up this name> I'm completely fascinated by all the unusual creatures/organisms that appear in or grow on my reef unexpectedly. It's great to have WWM as a resource to help identify them, and to have your personal replies is just fantastic. Thanks again for your time. Best regards, Derek <Welcome. BobF>

Feather Duster  - 03/11/2006 Hello, my fishy friends! <Hi> Thanks for all the help - and the confusion (bristleworms, good or bad? 6-line wrasse, "really" reef-safe or not?)  ;-) <Mmm, welcome> I think I have found the answer to my question in the FAQ's, just trying to verify.  A couple of weeks ago I bought one of the small feather dusters (red/white head, tube about 3" long, smaller in diameter than a pencil).  I drip-acclimated him like I do everything, then put him in a crevice where the bottom of the tube would be in the substrate.  I never once saw him come out of his tube.  A few days later I noticed that he wasn't getting much light where he was so I was going to move him, <Mmm, best not to> but when I removed the tube it seemed empty.  I didn't actually watch the guy at the LFS bag him, but I left the tube in my tank just to be sure in case he was still in there. <Good> Now, this morning when I turned the lights on in my nano, there was a tan lump about the size of an M&M sticking out of one of my pieces of live rock. Once the lights went on, it started pulsating and eventually disappeared. The tank is about a month old and everything in it either came out of my 60-gallon tank or I bought as a frag.  Is that thing my feather duster? <Could very well be> I have a lot of small feather dusters in my other tank, but since the heads come directly out of live rock I don't know what their bodies look like.  If that is him, will he decide tube-life is not for him and make his new home in my live rock? <Will actually generate another "tube"... What a planet eh? Bob Fenner> Thanks! Spaghetti Worm? 8/23/05 Thanks for providing this excellent service. <Welcome> I've learned an incredible amount browsing through your FAQs.  My question has to do with what I believe is a spaghetti worm.  It never shows itself, and never changes position, but it sends out about 8 long, white tentacles, about 6-8 inches long.  My problem is that every so often, it emits a dense cloud of what looks to be organic material that eventually clouds my tank. <Ahh! Likely waste and/or reproductive products> Sometimes it's yellow-green, other times it is black. Is that stuff harmful?  Or could it be beneficial? <Likely a bit of both, but not very dangerous> I have a flowerpot coral, brain coral, couple of small starfish and a coral beauty angel.   My tank is 50 gal, with about 35 lb. live rock, and I'm using the deep sand bed method.  Thanks very much. Bob <Thank you for writing, sharing. Bob Fenner>

Really Weird Things Happening In My Tank: Bristleworms? - 06/11/05 Hi Crew!  I have tried to find out on your site and in my books about what happened in my tank 2 nights ago; if you can direct me, I would appreciate it! <<Can...and will.>> I was just admiring my 75 gal. tank which is over 1 year old, but I had just bought it off a friend who was moving and have been living the Life Aquatic for only 2 months now: I am really new at this, but I Love it! <<Me too!  Much wonderment to be discovered.>> I have a serpent star, lots of little blue-leg hermits, huge turbo snails, 2 conch snails, 2 blood shrimp, 2 Perc clowns and a yellow tang in with ~90lbs live rock and crushed coral sand bottom. The parameters are tested weekly (which are stable and healthy) and water changed every other week.  I have added a torch coral, frogspawn coral, a gorgeous bubble tip anemone, pompom coral, Ricordea mushroom, candy cane coral, green star polyps and pulsating xenia.  As I was admiring the beauty of the tank after work at about 7pm, Suddenly!: there was an explosion of milky-white liquid shoot up from behind the rock in the center of the tank.  I tried to see where it came from and then noticed another shot of white liquid shoot from the end of the tank, and a couple minutes later another shot from the other end!  I turned off the flow to see if I could find out what was happening from above over the rock.  It was coming out from the holes in the live rock!  And it continued to spurt from all over the tank in random places, clouding the water, but not appearing to affect the fish or the corals.  Then I saw "IT": A HUGE-ENORMOUS bristle worm slithering thru the rock (maybe 6" long and 1/4" diameter) and when the tail end got to the opening in the rock, blasted out another shot of white liquid! Then I saw here and there other small pinkish coloured bristle worms poking out of rocks here and there: they were ALL doing it!  So I Think I know the WHO part of the scene.  My questions are: WHAT were they doing and WHY were they doing it, DO they Do that ALL the time/WHEN will they do that again? Should I try trapping them and getting rid of them or is this a good thing that is happening???  I turned the power heads and skimmer back on and added 2 jugs of R.O. water and the cloudiness cleared up and I have watched and waited for 2 days, and everyone looks fine and don't appear to have suffered any ill effects and it hasn't happened again since: not that I have been around to witness anyway...Nature never ceases to amaze me! Thanks for any information that you can steer me to! Rita (of RnR) <<Well Rita, it would seem you have witnessed a spawning event.  Little to worry about as you have discovered.  Much more info to be found here, and at the links in blue: http://www.wetwebmedia.com/bristlewrmfaqs.htm  Regards, Eric R.>>

Feather Duster Lost Its Crown - 06/07/05 Hello, <<Howdy>> I bought a feather duster from my LFS 3 weeks ago.  Its seems to be doing fine during those weeks.  This afternoon, I noticed that the whole crown has fallen down and got itself stuck between my LR and my sand.  I looked at the crown and the crown seems to be intact.  I thought it maybe in pieces like shedding hair but it seems to be a full crown intact. <<Not uncommon.>> The tube opening has folded close a bit but no feather/crown on site.  I am afraid to pull the tube out since I am not sure if the worm is still in the tube or not. <<Don't pull out the tube.  The worm has dropped its crown for any number of reasons (have a read here and at the blue links listed at the top of the page: http://www.wetwebmedia.com/feather.htm).  If it's not being picked on or suffering from damage/poor water quality it will likely reemerge in a few days/week with a new crown.>> Read some article about the worm occasionally losing its crown but I thought it would be more like losing someone's hair, in many pieces, not one big crown. <<Nope..."many pieces" usually indicates predation.>> The question that I have is that the crown is that attached to the worm?  Is my worm still in its tube or is it attached to the crown. <<In the tube...give it a few days.>> thanks Louie <<Regards, Eric R.>>

- Strange Bristle Worm Behavior - We have a 265 gallon coral tank.  We have noticed for many months that we have some very large bristle worms and have been trapping them whenever we can. <If I could encourage you to keep these... most bristle worms with the exception of the super-large ones [12" or better] are harmless and in the larger sense desirable, part of the natural order of things, and fill a vital role in marine systems. Better to get a fish that would prey on these and keep the population under control.> We also have 2 large sumps full of live rock that are also attached to the main tank.  We were moving around the live rock in the sumps and when we went upstairs to the main tank the water was cloudy.  That is when we noticed that the bristle worms (more than we knew we had) were behaving strangely.  They all came out of hiding and began to wiggle.  Then they discharged this orange color stuff.  We caught about 18 bristle worms with just tweezers within about 15 minutes.  It seemed that whatever they were doing was more important than getting caught.  We have never seen this before and I have tried looking up bristle worm behavior and have not found anything like what we have seen.  Would you know what this is and why all of them were doing this at once? <I can take a guess.> They all came to the front of the tank to do this almost like they wanted to be in the main flow. <It occurs to me that many invertebrates have an amazing chemo-sense... the ability to detect certain compounds in the water, and these mostly relating to food items. My wild guess is that your disturbance of the rock in the sump likely let go detritus that the worms would normally construe as food.> Thanks for any help in advance. Kevin M. <Cheers, J -- > Feather Duster Hello, <Hi, Graham at your service.> We finally found your wonderful site of information.   <We're glad that you find the site useful!> We have a 75 gal. that has cycled.  It is about 1 month old.  We just recently added 2 Hawaiian feather dusters.  This morning we saw that one of them has completely left his tube with crown.  It also had a web like matter coming from it.  What could be the problem?   <Many times tube worms will leave their tube due to stress- possibly something is bothering it, too much current, or poor water conditions.> We are feeding it DTs phytoplankton.  We have a crushed coral substrate.  Will it be able to re-build its tube with that substrate? <Fortunately, in a healthy environment, the worm will be able to regrow its tube within weeks or months.> Thank you!!! <Take Care, Graham.> Joan Tipton

Fat Bristle Worms I read your questions and answers every day and I can not tell you how much help you have been to me. I think I have avoided a lot of problems by reading the daily facts and questions every day. <I know I have by trying to respond> I do have a question about bristle worms. I read several of Jason's answers (while you were diving) to various people about the fat bristle worms and they were not desirable. I have seen fat bristle worms in my tank, but to date they have posed no problems. I do also have the spaghetti sized bristle worms. I have a flame hawk and a long nosed hawk as well as a six line wrasse. What is the problem with the fat bristle worms. I never read anything that told me why they were not desirable? Maybe I missed something but I want to learn. <The fear is that larger (fatter) species, individuals might prove too predaceous> I have a 30 gal w/protein skimmer, (2) 301 power heads w/quick cartridges and 1 Penguin Bio Wheel outside filter 300. I have the above mentioned fish and 1 skunk clown as well as 1 blue yellow-tailed damsel. I have various fragments of soft and hard coral. My water parameters are very good. I don't know whether to be worried or not. <I would not worry> Thank you for all you do for this very enjoyable hobby! <You're welcome> I intend to purchase you book! I do spend a lot of time printing your articles so I have them for reference. Susan in Atlanta <Ah, I hope they help you as much as they have helped me in their production (leading forward). Bob Fenner>

Bristle worm behavior Hello Mr. Fenner, <Actually Steven Pro (part of the www.WetWebMedia.com crew) in this morning.> My name is Tori and I work full time with fish in the aquarium trade as head of a large fish room here in Washington. My question to you is, have you ever actually seen a bristle worm eat? <Not really eat per se, I have seen them scavenge around. Most that I have witnessed are rather small.> (I have the classic bristle worms in every picture, the red with the black ends, and white, spaced, bristles) I have a fifty gallon reef that's been up for approximately one year. I have a few fish (no more then seven inches total) coral, clams, shrimps and lots of filtration (as I said, its my business ;)). I have just embraced the bristle worm invasion in my system, and just decided its my little eco system no matter what, and if its nothing but Caulerpa, rock, and bristles, so be it. <I find most bristle worms to be harmless to beneficial scavengers. The seem most prolific in tanks that are over fed, as there is then an abundance of food for them to scavenge.> That said, tonight I was sitting looking at the tank, and noticed one of the very largest of my "pests" (9 3/4 inches because I measured him) <A rather large individual.> and all of the sudden it took a huge "bite" of Caulerpa! <Interesting! You would not have happened to photograph the event?> The mouth looked similar to a snails mouth with the disk teeth. Then it seemed to avoid the large copepods moving around it in the sand, and the little brittle stars too, and went back to the exact same branch of Caulerpa after painstakingly searching it out and finished it off! <A series of pictures of this would be great!> I was just floored! <I am a bit surprised, too. They are omnivorous, though.> I thought they eat clams and coral. <Mostly detritus, extra/uneaten food, etc.> So, I was hoping you may know of at least on other person who has actually seen one eat. <I have seen them swarm dead fish, but nothing like what you are describing.> Thank you again for all your time. live, swim, grow ~Tori Craig <I try to do the living and swimming part as much as possible, but I do have to try to stop the growing (mostly width-wise) now. -Steven Pro>

Feather Duster Question 3/8/04 Hey:  I have a feather duster question...  I have had one for about two weeks and now he starts coming out of his tube... but he goes back in if he gets scared...  Looks like he gets out and his crown is out and he looks around with it or something...  Is something wrong with him or is this normal..  Thanks a lot <It is probably normal.  Feather duster tubes are often damaged in transport.  It will be reconstructed in time if the animal is healthy and getting enough food.  Losing "feathers" from it's crown would be a bad sign.  Best Regards.  Adam>

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