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FAQs on Parasitic Marine Worm Diseases: Medicine Products/Manufacturers

Related Articles: Marine Parasitic Disease, Parasitic Worms, Roundworms

Related FAQs: Fish Worm Diseases 1, Marine Worm Parasites 2Marine Worm Parasites 3, & FAQs on Marine Worm Parasites: Diagnosis/Symptomology, Etiology/Prevention, Cures That Don't Work, Cures That Do Work, Flukes/Trematodes, Tapeworms/Cestodes, Leeches/Hirudineans, "Other" Worms and Worm-Like Parasites... Paravortex/Black Spot Disease, Anthelminthics/Vermifuges... De-wormers (Piperazine, Praziquantel...) & FAQs, Yellow Tang Disease, Parasitic Disease 2, Parasitic Disease 3, Parasitic Marine Tanks, Parasitic Reef Tanks, Cryptocaryoniasis, Marine Ich, Marine Velvet Disease Biological Cleaners, Treating Parasitic Disease, Using Hyposalinity to Treat Parasitic Disease, RoundwormsYellow Tangs, Tang Health/Disease

Praziquantel (Droncit), incl. PraziPro, Fenbendazole

For External:

Some commercial fish prep.s that contain organophosphates (Clout, Med-Aqua, Fluke-Tabs...)

Formalin is a biocide... kills all life. READ re its CAREFUL use on WWM

To Marco- Help with Moray Eel disease      3/15/18
<Hello Adrian.>
I could really need some help treat our infected moray eels. They have gotten a blood sucking worm that only attacks the eels. It look like brown hairy looking strings.
<Looks nasty. Can't definitely ID them, though.>
We have tried cleaner wrasse and shrimp and freshwater dip. My boss confirms its not anchor worms and we don't have any medicine currently to treat it. The only working solution we have found is removing it manually, but
they spread again after a short while.
<Can you get Flubenol 5% in Norway? (I think so) It's often used for e.g. chickens or pigs as well as fishes and kills a wide range of internal and external worms. Only use it in a hospital tank without sand (but some PVC pipes as caves) or use it as baths/dips. Siphon the bottom of the tank for any eggs (or cysts depending on what they are exactly. If you can't get Flubenol you can also try some product with Praziquantel.>
The eels came infected from Indonesia but it took a while before we noticed it. Best Regards Adrian
<Good luck. Marco.>
*I attached a picture of the worms

Re: Eel question and what gives
Now dewormers for marine fishes, Thalassoma     7/25/17

Hey Bob,
Thanks for the insight. Just a side note, these eye flukes, Neobedenia, seem unfazed by Prazi pro. May look into another dewormer.
<There are a few; listed on WWM>
Lastly, I can't seem to find much info on the Mauritius red cheek wrasse.
Have you had experience with them? Thanks , bob
<I do not; but this Thalassoma is not easily kept... too spastic, easily damaged. Bob Fenner>

FW dipping 3/28/13, flukes, Prazi use in DTs/Reefs        3/28/13
Hi crew!  I believe I have some of my fish have gill flukes in the main tank. I have a Flame Centropyge in a QT and did a dip on him today....holy cow!!! It was disgusting! He had 20-30 flukes on him and I never saw them on the fish. Anyway, I want to dip the fish from the main tank but I don't know if any of them are contraindicated for freshwater dips. Occupants are:
Solarensis Wrasse, Canary Blenny, Hi Fin Red Banded Goby, Sleeper Goby and  a Halichoeres leucoxanthus.  The Canary Blenny and the Sleeper Goby have been scratching for over a week but no one has spots. Of course the dip will be pH, temp matched and aerated. Thank you!  Jennifer
<These fishes/species are all good candidates for dipping, short immersion baths. Bob Fenner>
Re: FW dipping 3/28/13    

Thank you, Bob
<Welcome Jenn! B>
Re: FW dipping 3/28/13

Hey Bob,
 Just went to check on the Flame in the QT and he is hanging out at the top of the water right under the HOB filter. He's been in the QT 2 weeks. Is this normal considering all the flukes that came off of him?  Jenn
<Not unusual behavior... small volumes, being stressed by handling... B>
FW dipping 3/29/13

Thanks Bob. I didn't think he would make it through the night but so far he has. I have a issue with the main tank. Ok, here goes: I think some of the fish in the main tank have flukes.
<Trematodes are very common (ubiquitous almost) on marine fishes... some are quite species, genus specific; others more general in their parasitism>
 Reason I think this is 3 days after adding the Canary Blenny he started to scratch on the sand. A few days later the sleeper goby started to scratch, although he stopped a day or so later. Then the yellow wrasse scratched a couple of times.  Now the Sol<o><not a>rensis, who is like a dog, is hiding a lot. They are all still eating, no spots and all but the Blenny are hiding.  This has been going on for 8 days. I dipped the Canary Blenny and it looked like little worms were in the bucket but I can't be 100% sure they were worms. Also there were things that looked like little flukes, again not positive. I did dip the Goby today for 5 minutes. I didn't see anything come off him that I could identify except what I think is sand.
Finally, my question, should I 1. QT all the fish and treat with PraziPro?
2. FW dip fish, put back in main tank and keep watch? There is definitely something going on in the tank, I just can't figure out what it is. Sorry for the long email and thank you!
<You could try the Prazi... toxic to all worms... B>
Re: FW dipping 3/29/13

I've read that some have used PraziPro in a reef tank with no repercussions,
<Mmm, not likely "none">
 however that makes me nervous. Have you heard that it can affect the biological filter? My LFS told me that it could even though the PraziPro bottle says it won't.  Your thoughts?
<... won't affect nitrifiers, denitrifiers directly... but killing off large numbers, biomass of Vermes can have bad consequences... One should be prepared to counter, or move intentional livestock. B>
Re: dipping     3/29/13

I do have quite a few Vermes, red, pink and yellow ones I'd like to keep.
So it looks like they are going into the QT with the Flame and all will get PraziPro.  Thank you kind sir:) Jenn
<Ah, good, and welcome. BobF>

Fluke Problem Hello crew, I have two tanks in which a flukes (capsalid Monogenean) were introduced.  The specific type is Benedenia sp. I have found FW dips or clout to be very effective on these, however, since these 2 tanks are display aquariums I would rather not treat them with clout. <Agreed, only in extreme cases do I consider ever adding any sort of medications to a display aquariums.> Do you know how long an aquarium would need to remain fallow to prevent reinfestation once fish are reintroduced? <Most parasites can't live longer than 4 weeks without having a host.  So, if you left the tank fallow for minimum of 4, but preferable 6 then it should allow the pest to run through their cycle.> Thank you, Richard <Hope that answers the question.  -Magnus>

Butterfly with gill flukes? My double saddle butterfly has been breathing rapidly for a week now. It's not ich or velvet as I'm familiar with these diseases, and all of my fish have been QT'd for a month before introduction to the main tank. The bf isn't scratching, there are no spots on him, just the heavy breathing. I'm pretty sure he has gill flukes... <Stop! Where would these Trematodes have "come from?"> ...so I've been administering 50 min formalin baths (2 teaspoons Kordon's formalin/gallon) everyday for the past 3 days. Is this a sufficient treatment? <Possibly... there are more efficacious "de-worming" medicines... as you will see: http://www.wetwebmedia.com/fshwrmdisfaqs.htm> I've read that it's better to treat with formalin as a bath rather than constant exposure in a qt tank. <Yes... please read: http://www.wetwebmedia.com/formalinart.htm> So far, the butterfly is still eating well, not hiding, but still has the rapid breathing. I've also noticed that he has thread-like poops. Could he have internal parasites as well? <Yes... but very much more likely this is just symptomatic of the toxic formalin exposure> All other fish are fine, although I noticed a long stringy poop coming from the coral beauty (I've never seen her poop like this). Are internal parasites contagious? I've attached a photo of the coral beauty poop. Ammonia, ni trite, nitrate, 0 Salinity 1.024 pH 8.2 79º Thanks, Angela <Angela, I would suspend the formalin treatments, look into Praziquantel... what you are doing is too toxic to continue, not likely helpful... the fish do not have monogenetic Trematodes... unless you've observed these under a microscope I strongly suspect there is not a pathogen involved here. Bob Fenner> 

Re: butterfly with gill flukes? Ok thanks for the reply Bob. I actually went and bought Prazi-pro yesterday and administered an hour long bath as directed. I plan to do another bath 3 days from now. Are the baths ok or should I just treat long term in a qt tank? <I would take the latter route> So far no breathing improvement. <... sometimes these fishes do "just" breathe hard... perhaps environmental influence/s... maybe social... I would not panic re> He's still eating well. As far as the stringy poops, the BF has always had them (I never saw him poop in QT, and was suspicious of that. It's because the thread-like poops are very hard to see) I figured he had gill flukes because of the internal parasite signs...  <I do wish everyone had ready access to a decent microscope (I have a neat, but cheapy QX3 Mattel/Intel unit... that's fabulous) to LOOK before using toxic chemical treatments... as I assure you that orders of magnitude more livestock is "bumped off" by well-meaning aquarists than dies from actual pathogenic infection/infestation> ...but also I'm at a loss as to what other pathogen would cause the rapid breathing (he has no spots or other signs) -a <As stated... there is almost certainly not a pathogen present. BobF>

What's in Fluke Tabs? Hi Chuck! I bought the Fluke tabs. Do you know what are the active ingredients? It's not written on the product. Thanks! Dominique <The active ingredients are Mebendazole and Trichlorfon.-Chuck>   

Praziquantel Also Bob, I am wondering if you can help me. We have some incident of Trematodes in our system.  These worm/fluke is in the fish and when we fresh water dip the fish, the worm came off from the fish.  Some people I talk to say to treat with Praziquantel or PraziPro from Hikari.  Do you have any info as far as treating the entire system with PraziPro (side effect, other problems etc). Thank you, Fred <Ah, yes. For Trematodes, treating their systems as well as fish livestock, 2 to 10 mg Praziquantel/liter (or 7.6 mg/gallon)... the lower does for Monogeneans will do it, the higher for digenes. There are also methods (not applicable here) for injection and oral administration, baths... Cheers, Bob Fenner>

Re: Praziquantel Thanks Bob, what about PraziPro?  Is it safe? <Yes... is just Praziquantel and a stabilizing agent: http://www.uskoi.com/prazipro.htm>   I know it is a lot more expensive but no need to dilute. <Agreed> I heard you need to dilute Praziquantel with Vodka? <Heeee! Can use this solvent... or not> Also, how can you tell the difference between Monogeneans and digenes. Thank you, Fred <Mmm, sorry for the added confusion. I would not worry re the digenetic Trematodes... they can/will perish along with the rest or die out quickly enough due to the lack of intermediate hosts (Di as in two... two or more other life forms to pass through before getting to their determinate host (your fishes)...), as opposed to Monogenes that have a direct life cycle. Bob Fenner>

Cryptocaryon not responding to copper First of all thanks so much for your excellent website and advice. I was unable to find an answer to my particular question in your archives, I did try. I currently have a 5" Hippo Tang and 5" Blond Naso in quarantine- 20 Gal. bare bottom, fully cycled canister filter amm/0 trite/0 PH/8.1 Temp/80 Salt/1020 I recently purchased these fish and I am treating for parasites with Cupramine. My problem is the Naso has several cysts 12-15 "same ones" that have not dropped off after 7 days at 0.5mg/L confirmed by calculation and 2 different brands of copper test kits checked daily. I have been keeping fish for over 20 years and don't believe I have misdiagnosed what looks like a classic case of parasites. <Ahh, but what type?> But anything is possible. The spots appear a bit smaller than the common Cryptocaryon and obviously stay attached much longer. The Hippo looks clear and no new cysts on either fish since treatment started, they are eating and acting well but I am concerned that I wont be able to cover the life cycle of this particular parasite in the treatment time if they are not releasing from the fish as tomonts to be siphoned out or enter the free swimming stage. I did not freshwater dip them because I don't have a pH meter and have had bad experiences trying to get pH adjusted in the past. "chicken I guess" I do however have Formalin and would prefer to bath the Naso in that if you think it would be beneficial, or should I just wait it out. Thanks in advance Shaun <Mmm, am thinking these spots may be more subcutaneous... worms... not affected by copper in the water. I would try an anthelminthic. Please see here: http://www.wetwebmedia.com/vermifugefaqs.htm Bob Fenner>

Re: Cryptocaryon not responding to copper Thank You Bob, I think I will try the PraziPro I am assuming I should complete the Cupramine treatment and remove it from QT prior to starting the PraziPro correct? Thanks Shaun <Actually, I'd abandon the copper treatment... it's obviously not working... and it's obvious to me that you know what you're doing here... have kept up testing, physiological doses... more copper exposure will do no good, likely harm. I'd go with the de-wormer by itself. Bob Fenner> Re: Cryptocaryon not responding to copper Bob, Not trying to be a pain here just want to make sure we are on the same page. I'm not sure I made myself clear. Sorry. When I started the copper treatment I definitely had a crypt outbreak and all cysts immediately cleared except for the few persistent ones left on the Naso so I believe I am battling parasites also. With that info do think I should finish the copper treatment? and if so wait to start the PraziPro <I see... I would continue, finish the copper run AND start the Praziquantel... they are miscible. Bob Fenner>

Anthias with worms? Human influence opportunities... Important!  03/22/07 Hello again guys / gals. I notice my Ventralis Anthias has clear / white feces and am guessing he must have intestinal parasites. <Ahh... so wonderful to be able to influence such young, growing minds/awarenesses...> I was considering different medications to use and would appreciate your input on what would work best for my situation. The medications I am looking into are: Fenbendazole at 7.6 Mg per gallon Metronidazole Praziquantel and Paracide D Any suggestions would be wonderful, the fish has not lost weight, however  he is obviously losing nutrients somewhere. Thank you so much, Brian  Crenshaw <My REAL (why not?) advice is for you instead to invest in a copy of Ed Noga's "Fish Disease, Diagnosis & Treatment" (expensive, I know... and have chatted w/ him re... Maybe get the fish store to buy a copy for your use as well as theirs...) AND a QX-3...4...5? Microscope... and to LOOK here, way before dumping such medicines on your livestock... Much knowledge, discovery awaits you... which I'm sure (very) that you'll be sharing. BobF>

Parasitic worms I need some help!  My Hawaiian Dragon Eel stopped eating.   I notice that he has thin, tan worms all over his body.   The worms are about an inch in size.  The part that doesn't hook into the eel ends in a point.   Please tell me what I can do to treat this.  I know eels are sensitive to many forms of treatment.  He is a full size eel.  Thanks so much for any advice you can give.  Kelly <Mmm, need to have a definitive identification of these worms... to the phylum level. I suspect they're flukes of some sort, and could be treated with an organophosphate. I suggest a pH-adjusted freshwater dip (that will likely result in a bunch "letting go" for microscopic exam.) at this point. Be careful with netting the specimen and keep the dip tank covered and heavily aerated during this procedure. The dip by itself will not effect a cure... as the worms are likely of a type that have direct development and will still be present in various stages in the main tank when/if you return the eel. Bob Fenner>

Re: Parasitic worms Hi Bob, <Hi Kelly> Thanks for your response. I did do the freshwater dip.  It took 18 minutes for the leeches to let go. (not die, just let go).  Yes, I did say leeches.  I took some of the specimens to an aquarium today.  I was told that they were leeches. <Easy to see with some magnification (and specimens!)>   Unfortunately, these leeches like to live in the substrate.  I had 200 pounds of sand and crushed coral in my tank.  Well, with some help, I actually removed all the substrate and bought more live rock.  The substrate is totally infected with these leeches.  Just looking at them makes my skin crawl.  I am treating the substrate with Clout in a separate container. <This should "do it"> There are no more of these leeches visible in the tank.  Although, he does have two of the leeches on him.  Compared to the hundred that were all over him yesterday, I consider this a huge accomplishment. Once the eel settles down and does not appear so stressed, I will try to pick off the two remaining leeches.  This has been a very long project, but is well worth the effort to save this beautiful eel. <Yes> We have a Titan trigger fish with the eel.  She was sick in the past and had to be quarantined.  We now think she was being infected by the leeches as well. Since last night when we gave the eel a freshwater dip, the Titan has been extremely protective of the eel.  She lies right beside him.  If I am working in the tank near to the eel, she goes completely ballistic.  I have to say a full size Titan trigger and full size Hawaiian dragon eel are a nice match.  Although, I would not add anything else with them. Take care Bob. Kelly <Thank you for the progress report. Bob Fenner>

Grab Bag of Parasites? Please help with the following questions... <Sure thing! Scott F. here again today> - When it says 'will kill invertebrates' on copper medication, does that include shrimp, snails and crabs? <precisely> - Is copper also good for flukes? <I prefer Formalin-based remedies for flukes...> - What are ectoparasites? (Ich? Flukes? Velvet?) <Consult the WWM site for specific forms> - One of the remedies to get rid of parasites is to lower salinity to 15ppm. Will that also kill flukes and velvet? How safe is this on corals, snails, crabs and shrimp? <Hyposalinity treatment can work for some parasitic diseases...I'm not a huge fan of it. It can be harmful to inverts> - Will the banded coral shrimp also 'eat' ich and velvet and flukes from fish? Would this plus UV sterilizer be a good alternative to using medications? <The CBS will pick at some parasites...but it cannot get them all. A UV sterilizer is good at possibly stopping some of the parasites when they are free-swimming...I still use meds...> - Finally, in one of my 20g tanks, I'd like to keep one Banded Coral Shrimp and one Harlequin Shrimp. Will they be ok with each other? Will they be ok with reefs? <They should be fine with corals...But there may be some aggression between the two...Be prepared to move somebody> As always, huge, huge thanks for your help. Luke <A pleasure, Luke! That's why we're here! Regards, Scott F>

No Meds In A Display Tank! > <Sure thing! Scott F. here again today> >  - Is copper also good for flukes? > <I prefer Formalin-based remedies for flukes...> I've heard that Formalin is a big no-no in marine and reef tanks (hard on corals, will kill bio filtration, will kill live rock). No? Thank you, Luke <You are absolutely right Luke.  Under no circumstances would you ever dose this, or any other medication in a display tank.  Formalin should be administered only in a controlled environment such as a "hospital tank."  It is highly effective against flukes, however.  Follow manufacturer's instructions to the letter when you use this stuff.  Good luck!  Scott F.>

Formalin Works-But What About The Display Tank? (Flukes) Right, but flukes lay eggs that get deeply into the gravel sometimes (making them so hard to cure). So even if one does treat the fish in separate tank, you're still going to have flukes in the main tank, no? Thank you. <Well, the approach to many parasitic infestations is to deprive them of their hosts...Thus, the oft-recommended "fallow tank" technique is an efficient, drug free way to help eradicate parasites. No method is 100%, but this is a very effective method. Good luck! Scott F>

Is This Treatment A Fluke? (Use of Praziquantel To Combat Flukes) Is Praziquantel (Droncit) effective for flukes in marine fish? <This stuff has been used by some people to treat flukes effectively. It should be administered carefully, like any medication> How does it affect inverts? What would be the right dosage to get rid of gill and body flukes? <I would not administer this, or any medication in the display tank, regardless of the presence of inverts. The dosage that I have seen used to combat flukes is 1ppm in saltwater. I know a couple of people who swear by the stuff...Have not used it personally, however.> I hope it still works in marine aquarium and is easy on the inverts... It's magical in FW, no stress on fish, ok for bio-filtration etc... Thanks, Luke <Well, Luke- Praziquantel is certainly something that is being used more and more these days to combat flukes in marine fish. You could also use Formalin-based medications, or those containing Malachite Green...It's worth a shot, however, if you're up to trying it...Good luck! Regards, Scott F>

- Wasting Disease - <Hello, JasonC here...> Hi crew, have a problem I haven't been able to find much on. Have a Sebae clown, wild caught, about 4 years old; always been in perfect health. Recently, I moved him to a larger tank, fish with some inverts, no anemones (yet). About 2 weeks later he developed Popeye, one eye, which I successfully treated with Epsom (thanks!). He still has a good appetite, even still has that pearly iridescence around the white bands that fresh-caught clowns have, BUT, he is beginning to lose mass; first, developing the typical pinched forehead, now progressing rearward both above and below the lateral line; no other clowns in the tank, other specimens unaffected. He eats and comes out less but is otherwise still pretty normal. <So you do see the fish eating... it would seem to me with the other occupants, this fish might be getting less that its fill.> His offered diet hasn't changed, if anything is better because I am feeding a large French and Atlantic blue tang, and very wary of HLLE, so they eat better than I do. My past experience is that this guy is headed for checkout, but its been a while, and if there is anything I can do I want to do it, so, suggestions? <Well, isolation might help - make sure the fish is eating well and without competition from the larger fish. Also, because this is a wild fish, it is also more likely that it has an internal parasite (or two) that are competing for the same nutrients, quite possibly nematodes or Cestodes [tapeworms]. Both can be treated - you should be able to obtain Praziquantel [for the Cestodes] and/or Fenbendazole [for the nematodes] from your local veterinarian. I would work with one of these at a time, and administer in baths for 2-3 hours. More information on these treatments can be found in the Edward Noga book, Fish Disease, which while expensive is very complete... and an eye-full.> Thanks, Steve J. <Cheers, J -- >

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