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?
Thanks,
Emily
<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>

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.>>