Could a worm be harming my fish? 1/7/10 Hi there, <Hello> About a week and a half ago, I notice this worm in my tank, it was long (maybe 6 inches long 5-7mm in diameter, and can stretch I think), brown and looked as if it had bumpy skin, or very freckled skin. One end of the worm seems to 'suction' itself on the live rock and move along in that way. I'm not sure what kind of worm this is, but I thought maybe that's the way it eats off the live rocks, so I didn't give much thought to it and let it be. On Sunday this week, I put in a Firefish, yellowtail damsel, and clown fish <All social animals...> in my tank (about 60 gallons, it had just completed cycling). They all seem very peaceful, and doesn't appear to be any bullying etc. Today, when I was feeding my Firefish, I noticed on one side of its body, there's a circular bulge, and there is a small indent in the middle of the bulge - like a ring. If you look front on, you see the bulge sticking out, but if you look side on, you can see the indent in the middle. The size of this 'circular bulge' is similar to the size of that worm I mentioned. Could that worm have 'suctioned' itself on the fish and caused this? Or could it have been something else? <Yes and yes> Oh, and yesterday, I fed my fish frozen brine shrimp, and the Firefish ate some and then threw it up pretty much straight away. I looked on the forums and read that maybe the fish just doesn't like the food, so I put in a bit of flake food to see if the fish would throw that up too, but it ate that just fine, and has been eating fine this morning. I don't know if that's relevant to whether it could have caused the bulge since it looks as if it's an external thing. Right now, the fish doesn't appear to be doing anything out of the ordinary. I would send you a photo, but my camera has a dead battery so I'll try to post one when it finishes charging. Thanks for your help, KC <I'd keep an eye on the worm... and read here: http://wetwebmedia.com/polychaewmcompfaq2.htm and the linked files above. Bob Fenner> Pic - Re: could a worm be harming my fish? 1/7/10 Hi again, Here's a picture of the fish, it's rather blurry... you can sort of see the bulge, I couldn't take it from the side on to show you the small 'indent' because it just comes out as white on the camera. After paying some more attention to the fish today, it doesn't seem as if it's swimming around as freely now. Most of the day, it was hiding in one of the holes as if it's sleeping. When it does come out, it's not swimming around as usual and just seems to be hovering in the water, in the middle of the tank. And it's not interested in any food either now. Any idea what could be the cause of this? And what can I do about it? <Could be predation... from the worm or... Or resultant from a physical trauma... or...> I tested my water a few hours ago.. Salinity: 1.023, PH: 7.8, <A bit low> Ammonia: 0, Nitrite: 0, Nitrate: 0, KH: 9-10, Temp:81-82 Thanks! KC <Welcome, and keep reading... on WWM, re Microdesmids, your other livestock. Bob Fenner>

Re: Pic - could a worm be harming my fish? 1/7/10 Hi Bob, Thanks for your quick reply! I've been looking through the pics and some posts in the worm FAQs to find the type of worm I've seen in my tank to see if they're harmful or not but I can't seem to find a match. Any idea what type of worm it could be - that suctions itself to the surface and moves flat along the ground/rocks? <Need pix Kitty... even then, there's a bunch of worm species...> And possibly harm fish... I would take a photo of it, but I haven't seen it for a few days. <Try baiting it out toward lights out/evening> Also, do you think it would be a good idea to somehow get rid of the worm? <Mmm, likely so... this one's a bit too large for me> I wouldn't want it to do the same thing to my other fish - if it is the worm that caused the injury to my Firefish in the first place. Thanks again, KC <Welcome. BobF> Re: could a worm be harming my fish? 1/7/10 Hey there, Thanks for your reply Bob, it seems we have two separate emails going on (this one, and another one where I sent you the photo) so I'll just reply to this one from now. Well, my Firefish just died =( I've been trying to figure out whether the worm could have really caused this. At first, I thought it could quite possibly have been the worm because the size of the 'bulge' and the shape matched the worm. Tonight, though, when my fish wasn't looking too good, I noticed it kept twitching it's tail violently every 10 seconds or so, as if it was trying to get rid of something, but I didn't see it scraping itself against rocks or anything, and it was breathing rapidly. Right after my fish died, I looked at it again since it'd been trying to hide at the back, near rocks for most of the night where it's kind of dark, and realized that the bulge that was initially just white with an indent was gone, there was no bump but instead there were red scratches on its skin. Now I'm wondering, could it have been internal? <Possibly> Or could the fish have been scraping at the wound? <Also could be...> Or maybe something eating away at it on the skin? I'm probably way off... <We can only guess here> I just looked briefly at the link you sent me about the bristle worms. (I'll read it more thoroughly tomorrow since it's really late where I am... I was actually about to go to sleep when I noticed my fish not looking so good =( ) I didn't notice any bristles on the worm, and I never saw any bristles on the body of the fish either. Do all bristle worms have visible bristles on their body? <Mmm, no... some have very little podia, bristles> Sorry for all these questions but I'm pretty new to this hobby and am trying to learn as much as I can, and I don't want something like this to happen again to my other fish. <Understood> Anyways, I've attached a photo of the red wound on the fish along with this email. The photo was taken about five minutes after the fish died. The purple color around its head came on after its death, but you can see the red area I was talking about.. I also attached the original picture that I took and sent you earlier today when I could still see the white bulge. Thanks again for your help KC <Welcome dear. BobF> Re: could a worm be harming my fish? 1/7/10 Hey there again, <Hello Kitty> Just as I said I hadn't seen the worm for a few days, it came out of hiding! Well... sort of... you can only see a tiny part of it, most of it is still in hiding. I'm not sure if you can tell what kind of worm species this is since the photo is rather blurry, but here it is anyways. I'm going to try and trap the worm tonight, and see what happens :) KC <Mmm, can't make much of anything here. BobF>  Re: could a worm be harming my fish?  1/12/10 Hey Bob, Wanted to say thanks again for all your help =) I haven't had any luck luring the worm out, but will keep trying. KC <Don't give up Kitty. "Persistence pays"... keep trying different meaty baits, traps... you'll "get 'em". BobF>

Not So Friendly Ribbon Worm  11/22/09
Bob and WWM Crew,
<Dan>
Thank you for the outstanding service to our hobby. Am writing for some innovative advice. I've got a large (easily 12+ inches) Nemertean (Ribbon Worm) navy blue color with jagged white stripes. In fact, he is the
spitting image of the worm portrayed in the title bar of your Nemertean FAQ page. While he is actually an attractive and interesting animal, he is decimating my snail population. We've watched helplessly night in and
night out as he stalks Nassarius and Cerith snails, injects them with his proboscis and drags them into his lair...
<Very nice prose>
My daughter calls him Nessie. I'd like to find a way to trap the little bugger and transport him to a secluded spot in my multi-tank refugium (a snail-less spot that is). However, here is the rub - I spent many months
designing my aquascape and the live rock he has chosen as a home is at the very bottom of a large pillar I built using fiberglass rods drilled through rock (I liked the aesthetics of having a rock pillar that broke the
surface...).
<Me too... What is that phrase someone penned for Ronnie Raygun? "Tear down that wall!">
Disassembling the pillar is a lengthy and somewhat dangerous process. My only plan is to remove the remaining livestock and wait to see if he comes out to search out a new (more easily removed) home. Any other ideas?
<Yes... a baited trap in the way of a meaty item (perhaps a defrosted bivalve from a grocery store)... placed in a glass or sunken plastic soda pop bottle... and periodic checking to see if the worm is inside during the night>
Know anybody who wants an attractive, well-fed Nemertean?
<Mmm, Craig's List?>
Thanks,
Dan
<Welcome my friend. Bob Fenner>

Black Roundworm Infestation?  11/22/09 Hello! <Hi there> Thank you for taking the time to help me and everyone else! <Welcome> I recently set up a second 55g QT tank by using some of my old QT aquarium's water. I let it cycle for a while. After it had mostly settled in (running for about a month...everything tested fine), I put two Watanabe Angel's into the QT. After a 2-week QT and a freshwater dip, they went into my main aquarium. Two weeks later, and I found a terrible tiny black worm infestation. They're literally everywhere covering everything in my QT. They're only about 2-3mm long. I have never seen these before...and don't know if & how I should treat for them. What are they?? <Mmm, can only see/say worms of some sort. And not likely deleterious> I should also note that I used dry base rock (and cleaned)...so they didn't come from live rock or anything. <Might well have been in the water, perhaps in or on the Genicanthus> Additionally, the male Watanabe has never ate anything, no matter what I've done. He's starving away, and now I'm wondering if these worms have anything to do with it. <I would be treating this fish with an anthelminthic. See WWM re... perhaps Levamisole... or Prazi- if you can't find it> I've never seen them in my old QT aquarium (don't know if they were just in balance...or didn't exist in there). The new QT only has 1 damsel and some blue legged hermits and Nerite snails. Old QT: 10g with 10g sump, 1 Firefish, blue legged hermits, Nerite snails, 1 urchin...used dry base rock. It's been running about 1.5 years (never had to treat for anything.) New QT: 55g with 20g sump, 1 damsel, blue legged hermits, Nerite snails, 1 urchin, used dry base rock. Running about 2 months total now. Thanks in advance. Please let me know if you have more questions. Nikki <I'd leave the worms be myself. Probably will cycle out of their own accord. Cheers, Bob Fenner>

Worm ID   8/3/08
Let me start off by thanking you for all of the information (especially your honesty about the aquatics industry, I haven't had a wink of sleep, but I can't say you didn't warn me in your FAQ's). My husband and I have recently purchased a LFS (not so aptly named "The Jungle").
<Congrats!>
One of my customers, and I, have discovered new worms in our tank within the last few weeks. I'm sure I should know this, but I've only been a saltwater hobbyist for a few years with no "official" education. Anyways, both of our worms have the same characteristics with the same natural habitat. Neither of us can identify these worms, Mine is solid white and creeps out of a small hole in my live rock and my customer's is black with a white crown. The worms are not exiting their homes in the live rock, but simply slowly and fluidly pulling out for inspection of surroundings. No livestock seems to even be remotely interested in the newly found habitants. The
worms are probably only 3mm in diameter and they have not made themselves visible until the tanks were due for their bi-monthly water change this weekend. They do not look like bristleworms, but rather more like freshwater tapeworms.
<Mmm, not these... are all internal parasites...>
P.S. We have owned our LFS for 5 weeks and already sold three copies of "The Conscientious Marine Aquarist."
<Call my yacht broker!>
I have been reading your website for years and just with that I have made it through a fraction of your knowledge.
Thank you for everything!
Krystal Wessels
The Jungle
<Again, welcome to the trade. Do know that there are thousands of such worm species... the vast majority of which are much more beneficial than potentially deleterious... If anything, I might address the conditions that are allowing this population... vacuuming gravel, cleaning other filter media, cutting back on feeding... But, not to worry... am VERY sure you have much else to take up your time! Bob Fenner>

Amphipod/Shrimp Question... and Rock mining worm?? 6/20/08
Thank you guys for hosting a great site! Most of my questions and concerns have been addressed by browsing your QA's, but, alas, I still have more questions!
<Fire away.>
Background: 29 Gallon, 4 weeks old, 35# LR (UBER LIVE at that).. dual powerhead, emperor 280 bio-wheel mechanical filtration, protein skimmer on order, installing in 3 days. Ammonia, Nitrite, Copper and Phosphorous are at lowest range for my test-kit, near zero. Calcium 460ish (high). Ph is 8.0, target 8.2. KH is at 10. Temp is (cringe) 81-82 but a temperature solution is in sight.
<Temp is fine as long as it is stable.>
Living things I selected to put into tank: 2 young (1" ish) captive-bred Ocellaris. 10 Nassarius snails, 8 turbo snails and 1 small rock with 8 purple Mushroom corals.
<Ok>
Living things that came with the rock: Aiptasia Anemones (treating with a calcium paste stuff directly applied, made by Blue Vet); tiny starfish (Probably Asterina, not out of control), tiny (supposed) brittle stars hiding in rocks acting like filter feeders (their leg shape is too distinct to be anything else I've seen, also seems to fit with behavior);
<Micro stars are very common and harmless.>
HUNDREDS of various feather dusters (up to 3/4" while out), spaghetti worms and other types of "happy" filter feeders; 4 brown w/green center zoanthid-polyps; 2 (or more) small red and purple (bi-color?) bristle worms, 1 mystery white-tipped polyp (waiting to see how it grows) and the two critters I am concerned about...
I only wish I had a camera to photo these items, but...
Concern 1: possible shrimp or amphipod. it was seen in the light, moving like a bouncy flea along the sand. It is approx 3/16" long and banded in a red/white pattern like a red banded millipede, but with white instead of black. It remained curled up while bouncing. No noticeable larger front appendages, but, that isn't saying much with the size of this critter. Before I scared it off under a rock by looking at it, I sat and watched it dig in the sand like a dog in a cartoon digs in the yard for a bone; it never burrowed, just sifted and inspected. I don't know what this critter is, and if it is potentially a pistol or mantis shrimp... it looks like a very opaque amphipod... kinda. I R BRINY NOOB. Any information you have would be great.
<Sounds like an Amphipod of some sort, I would not worry about it unless you see it doing something harmful, and I doubt you will.>
Concern 2: thing, maybe worm. Black, tube shaped, lives in hole, doesn't come out. (now, with IQ) The hole is shaped like a miniature Hot Tamale Candy, or an elongated circle, and is approx 3/32" wide, and perhaps 3/8" long. The sides are unusually parallel. Inside this hole, *appears* to be a living, black, "single-tube coffee stirrer"... it will retract slightly when we use the turkey baster to disturb the algae (our first bloom, don't want it to settle)... but, the STRANGE part is... it seems to be mining out the rock.
<Many creatures will borrow into rock to make their own home.>
The best way to put it is that the barely visible part of this animal is a conveyor belt. every second or so (irregular timing) a tiny grain of sand will come down the top-outer side of this coffee-stirrer-worm-thing (not from inside the tube, instead it is magically balanced on top) and drop off onto my brown zoos. It has never come out of the hole in the slightest, it reminds me of a discovery channel show on how they bore
tunnels now, with the conveyor of rocks coming out and dropping off. the diameter of the tube opening doesn't seem to be an irregular circle, it seems to be VERY circular. My first guess was Peanut worm, but, that just didn't fit, this is hollow.
<Interesting, my first guess would also be a Sipunculids/peanut worm.>
There is another hole in this same rock the SAME shape and dimensions... with sand coming out 1 grain at a time, just no visible "coffee stirrer" in it.
<I'm guessing its the same thing, just deeper borrowed.>
I almost wonder if this *thing* is the last survivor from Roswell, NM.
<Get some tinfoil hats ready! Might want to try to contact Dr. Ron Shimek over at the Marine Depot forums, IDing these types of creatures is one of his specialties.>
While I have someone with knowledge reading, I'll go ahead and ask if you think my tank has space for 1 royal Gramma,
<Yes>
1-3 shrimp (cleaner, maybe a peppermint for Aiptasia)
<Sure>
2 green "clown/gumdrop" gobies,
<Be aware that these are very difficult to feed often, mostly eating Acropora coral in the wild.>
and months later a Flame Angelfish as the main show fish.
<The tank is too small for this fish unfortunately.>
Any suggestions you might have for these two mystery critters would be great.
-A. Beretta
<Chris>

Spag. worm control   4/26/08
Hi Robert, would you mind if I combined this email with another question I had?
I've been asking everyone and nobody seems to know. Do you think you could help? I need something that is reef-safe and will consume spaghetti worms. I know they are beneficial, but my tank has become oversaturated with them and I'm starting to think that they are irritating the hell out of my softies. I know that CBS and Arrow crabs will eat Bristleworms, but will they go after Spaghetti worms as well?
<Should, yes>
I've seen Red Scooter Blennies go after bloodworms, would they go after the Spaghetti worms? (Same size/shape) Any help would be appreciated. Vince
<I'd go the suitable crustacean route here myself. BobF>

White worms? SW, comp.   2/14/08
Hello, hope all is well with the wet web crew, happy belated new year! I need some help to ID some worm like critters who recently took over my sand bed and are now on my rock. I did take the time to review your worm ID sections, but the only thing close was a pic of your spaghetti worms showing thin white strips, almost hair like, spread out across the live rock, but this is not what I have.
<There are thousands of worm species... several phyla... mostly microscopic>
Tank background information: I have is a 10 gal mini reef with Aqua Remora hang on Protein Skimmer, mechanical filtration, live sand bed (which I supplement with a few pounds a couple times a year), lots of live rock and good water quality. I am just starting my third year with the same tank. I have the basics, xenia, polyps, hammers, leathers, one clown fish, one yellow watchman goby and one emerald crab (the first and only emerald I ever put in the tank).
<... all this in a ten gallon?>
I faithfully conducted 25 percent water changes weekly using RO water for LFS. Because of this site's advice, I have had very few problems (seriously, thanks a lot!). From what I have read, it is possible that what I have is harmless, may have came in the form of larvae (seeded my tank with live sand activator GARF once) and it does appear to feed like a worm. They are relatively new, last six months or so, but are now "taking over my sand bed," living in the rock and in between the polyps, etc. The must have a cement gland because they use the sand to build an anchor like cavity and they can actually throw themselves on the live rock by hurling their bodies to swing the sand-made anchors into crevices on the rock (it's actually pretty cool to watch them crawl p the rock in this fashion. You can easily brush them right off except when they get into a nook and cranny that can't be reached unless you use tweezers. In the sand bed, along side of the rocks they build like a chimney pipe.
<Fancy term, they're tubiculous... tube-building/living... still thousands of possibilities, a few phyla>
I do not have a camera and can't draw to save my life. This description is all I have. I am concerned about the volume of them and the possibility of a nutrient problem, but everything checks out water quality wise (nitrate, nitrite, calcium levels, water hardness, PH, etc.). I will soon be going to a larger tank in the spring and don't want them to follow because they are turning the top layer of sand into course like clumps and this can't be good for the live sand bed. I am hoping for an ID and a natural way of eradication (other then the tedious act of picking all them off each, which some will inevitably be missed). Please help me if you can, thanks from Long Island, NY.
<I don't think these worms are a problem, nor will be. If it were me, mine, I'd leave them be, continue the maintenance you've been doing. Bob Fenner>

Huge Peanut Worm and Bristleworm - 1/23/08
Hi Crew,
<Hi Jeff>
Getting back in the hobby after a 3 or 4 year hiatus (after moving from KC to ATL).
<Wonderful! I see in your follow-up mail that it’s a 28g nanocube – neat!>
I have 30 lbs of live rock and a small CUC. Last night I noticed what I think is a HUGE peanut (Sipunculid) worm. He was coming out of one rock and going into another. When I shined a light on it, it retracted into the lower rock. I could see the 'fuzzy' head and it is tan in color with black bands, so I am pretty sure it is a peanut worm.
<Does sound like it, except for the part about it coming out of one rock and going into another. They’re usually fairly stationary. Did it come completely out, or was it just reaching out/exploring? Maybe he was looking for a new home, perhaps something with a nice view [grin].>
However, this thing is thicker than a pencil when stretched about 4 inches from one rock to another. Do these guys really get that big?
<Yes, they do. Supposedly, they can get up to around 6” in length, but most we see in aquariums are much smaller. Thankfully, they’re all harmless detritivores.>
I read somewhere that in tanks that are fed sparingly they can starve to death.
<Sadly, yes.>
With this guy being so big I am worried about the water pollution that could result from his death. Should I try removing him?
<I understand your concerns, but I wouldn’t. Chances are, you wouldn’t get him out in one piece. Plus, you’d have one heck of a time just trying to grab hold of him. They’re very quick! I’d keep an eye on the situation. If you notice your hermits gathering at the “front door” of the Sipunculid’s "home", I’d take the rock out and try to flush out any remains. You can use something like a turkey baster and saltwater. Until/unless that happens, I’d continue to enjoy him.>
I also have a very active fireworm (grayish pink with setae on its sides). As far as I can tell he is about 5 inches long. So far, he has not bothered any of the 8 snails or 2 scarlet hermits I have.
<Have seen some this size+ in my tanks, and although I’ll admit they do give me a slight case of the “willies”, they’ve never been a problem. Just depends on which type you have.>
Is there any way to definitively tell if this guy is friend or foe?
<Yep, if he eats your corals, he’s foe! Sorry, couldn’t resist! There are two commonly discussed hitchhiking amphinomids/bristleworms: the notorious coral/gorgonian eating Hermodice canunculata (aka the “Bearded Fireworm”), and the scavenging/beneficial Eurythoe complanata (common bristleworm). The less common Hermodice canunculata usually has bright red/pinkish areas (gills) at the base of the setae (“bristles”), while the more common Eurythoe complanata does not (all white). Also, the “bristles” appear more compact/densely arranged in Hermodice spp. compared to Eurythoe. It’s a distinctly different look that stands out once you know what to look for. There are also some differences regarding their heads (caruncles), but you’d have to get in close to see them. Both, however, can sting the living daylights out of you, so be sure not to touch them with your bare hands!
Getting back to the friend or foe issue, if you've got a common bristleworm (Eurythoe sp.), no problem. They're mostly harmless/welcome additions that add to the diversity in a reef tank. Unlike most crabs that I consider guilty until proven innocent, these worms should be considered innocent until proven guilty. They’re often wrongfully blamed for killing fish, snails, shrimp, etc., when in reality they’re scavengers/detritivores that are not equipped for grasping/killing healthy livestock. For example, they don’t have the eversible grasping jaws that a predatory Eunicid has. Bristleworms don’t have jaws at all. What they do have is a sort of rasping device that essentially “licks” the food into the worm's mouth. These worms sniff out the dead, or dying, and help keep our tanks clean. If that Sipunculid dies, a bristleworm will be one of the first at the “dinner table”!
One thing of note that I’ve come across regarding amphinomids/bristleworms is a general rule of thumb stating that if the worm is larger than the diameter of a pencil, that you should consider trapping/removing it. Personally, if it’s not doing any damage, I’d leave it. On the other hand, if what you have is definitely a fireworm, Hermodice canunculata, I’d recommend removing it. If you see it out and about, simply use some tongs and carefully lift it out. Otherwise, you can use a commercially available trap or homemade version. There's a wealth of information on this at WWM and on the internet. Please see these links for photos and more information regarding worm diversity:
http://www.wetwebmedia.com/polychaetes.htm
http://www.reefkeeping.com/issues/2003-04/rs/index.php
http://home2.pacific.net.ph/~sweetyummy42/hitchworms.html>
Thanks in advance for your help,
Jeff
<You're very welcome! Take care -Lynn>

Re: Huge Peanut Worm and Bristleworm - 1/23/08
<Hi Jeff>
Sorry, forgot to mention that this is a 28 gallon nanocube.
<Thanks! -Lynn>
 

Spaghetti worms - marine 1/14/04
I've looked and looked and looked and can't really seem to find the answer to this questions, so could you PLEASE HELP???  Are spaghetti worms something to worry about in a salt water aquarium tank?  
<they are very helpful... detritivores. I'm not sure where exactly you were looking... but a simple keyword search on Google or another large search engine turns up hundreds of references to these desirable denizens of marine substrates>
I've just discovered some coming out of the live rock.  Let me know if they need to be fished out or are actually a good critter to have in there.  THANKS!   Jen
<they are as good as gold if you could breed and sell them. Keepers. Anthony>