Dealing with creepy-crawlies on your fish?
I’m sure you’re thinking one thing:
Yikes!
The good news is…
Treatment is pretty simple.
And once you get rid of them – they won’t come back. (Assuming you quarantine any new fish properly.)
So, let’s dive in!
What are Fish Lice and Anchor Worms in Goldfish?
Fish lice and anchor worms are two common parasites that prey on our finned friends.
They are often found on fish at the pet store.
Unlike many goldfish parasites, these two buggers can be seen with the naked eye.
Lice look like little green specks:
Anchor worms look like sticks or strings sticking off of the fish:
As they chew on your fish, your fish may get super irritated – scratching itself, flicking its fins, maybe even hitting itself on things in the tank or jumping out of the water onto the floor!
Both of them lay eggs.
Both of them attach themselves onto your fish to eat it alive (eek!).
And both of them have the same treatment.
How to Treat Anchor Worms & Lice
Treating anchor worms and lice QUICKLY is critical.
Why?
Because the longer they are left untreated… the greater the chance is that the fish won’t make it.
Some people recommend pulling the bugs off using a pair of tweezers, then swabbing the lesions with hydrogen peroxide.
Now:
The problem is this method doesn’t get rid of the eggs they’ve laid in the tank.
Once the eggs hatch and the larvae are swimming free…
… It’s only a matter of time before the problem comes back.
Yep, this means they can still get it again.
Getting rid of the eggs is actually the most important step to get your fish to totally recover.
The truth is…
By the time you actually see the parasite on your fish, it’s already laid lots of little eggs that are waiting to hatch.
Look:
Pulling off the parasites is a great place to start.
But using the right medication will take care of those sneaky little eggs lurking in the tank.
In the past, a pesticide called Dimilin was the treatment of choice.
But it’s expensive, super toxic and hard to get.
This newer medication containing Cyromazine (the active ingredient) is just the ticket.
You can get a larger size if you need to treat a pond.
Secondary Infections: Prevention is Better than Treatment
The scary thing about these pests is that they can create red spots or sores on your fish, which are little wounds…
… Wounds that can become infected by bad bacteria.
With many parasites, many times the parasite itself isn’t even as dangerous as the infections that can follow!
Preventing secondary infections is the best way to deal with them.
I recommend using KoiZyme throughout treatment and several weeks afterward to help protect the fish from infection.
KoiZyme is a totally natural product that contains good bacteria and nutrients to help prevent bad bacteria from trying to colonize on ulcerations on your goldfish.
It is safe to double the dose… in fact, it’s very difficult to overdose with this product and many fishkeepers report no ill side effects with a triple concentration.
Another tip is to salt the water at 0.3%, which will help reduce osmotic pressure on the wounds and expedite the healing process.
KoiZyme is safe to use with salt.
How to Identify Anchor Worm on Your Goldfish
Diagnosing anchor worm on your goldfish is pretty easy.
Anchor worms have been described like a…
Stick.
Splinter.
Or…
Worm.
The Copepod has a pronged head, shaped like an anchor.
It burrows this under the fish’s skin to suck it’s blood.
(Only the females do that.)
The worms themselves can be many different colors, from red to brown to light green.
Needless to say, fish with anchor worm can feel pretty uncomfortable, and the red sores are a sign of the irritation from the pest.
Here’s a video of someone manually removing worms from their fish with tweezers:
Again, Cyromazine (the main ingredient in Microbe-Lift Lice & Anchor Worm) is the way to go for goldfish anchor worm treatment.
Related Post: Treating Camallanus Worms in Aquarium Fish
How to Identify Fish Lice
Lice are nasty little critters.
They have a long needle they stick into your fish to suck it’s blood.
(I’m not making this up.)
They are also carriers of other fish diseases!
You can identify them as little green specs that look a bit like a dot of green algae on your fish.
Close up, they look like a really freaky, disc-shaped alien creature with dark eyes.
Lice makes your fish feel itchy and scratchy.
Treat them quickly with Cyromazine containing products to make your fish feel better!
Parasite Prevention Tips
Anchor worms and fish lice are highly contagious.
One fish carrying the disease can quickly contaminate all the fish it’s exposed to.
So:
It’s really important to quarantine your new fish to catch it before it spreads, infecting your existing collection.
Sometimes your new fish won’t show signs of them for the first week or so, until later on you notice something clinging to your pet.
Remember:
I always say, if something shows up during quarantine – that means quarantine is doing it’s job.
It’s far better to deal with something away from your main display tank than to risk the health all of your finned friends!
I also give a complete quarantine procedure in my book, The Truth About Goldfish, which teaches you how to ensure you how to safely remove all parasites from your goldfish.
What About You?
Are you dealing with an outbreak of anchor worm?
Are lice crawling around on your fish?
I want to hear from you when you drop your comment below.
Image credit: BannokStockPhoto, Shutterstock
Could be planarian worms, those are harmless. But indicate the tank is dirty.
my tank is infected with worms can out of date food be the cause of my goldfish being infected, can they harm humans with contact with them
Could be planarian worms, those are harmless. But indicate the tank is dirty.
So I noticed my two black butterfly tails both have these little specs on the sides of their tummies. They don’t seem to have behavioral symptoms of fish lice, and none of my other fish have the specks. Is this just a color thing that black fish have? Or is it lice? If so why? I just did 4 50%-25% water changes in the past week. One yesterday. I have a twenty gallon with four smallish fish including these. Only these two are black. I have MinnFin, would it be ok to treat with that? My water levels are all good, what’s should I do? And can I do something to not to water changes 24/7? I have a filter.
Probably a color thing. You could treat with MinnFinn, but it doesn’t sound like lice and it probably isn’t black spot disease (your fish would have to be in a pond with snails). 🙂 For water changes, you have to go by your water test results. Ammonia/nitrite problems only require those kind of frequent water changes.
Thank you so much! I was very concerned! Water changes have really been a pain since my siphon broke, and this really puts me at ease. That was also the quickest repsonse, I just left for a minute! 😉
🙂
My goldfish (6 of them) have red bumps with white stick looking things sticking in the middle of the bump. Family member added a big goldfish that had 2 bumps on it like this. Does this sound like anchor worm?
Yes that is anchor worm for sure.
Put some minnows and tadpoles in our pond from a ditch. Mistake. Our goldfish ended up with anchor worms, etc… several died… I did a 100% water change and clean out. Treated the pond with micro-lift for anchor worms and lice.
Everything is back to normal. Hard lesson learned. Don’t put things in there from the ditch, etc… LOL Quarentineand prevention is the best and right way to do things!!!
Eek, thanks for sharing your experience Jason – glad their out of the woods now.
please help. i have spent over £200 on 3 lots of fancy fish over the past 3 months. every fish has died with anchor worm. is it my fault, do i have to totally empty my tank and fumigate before getting more fish. i feel as if i am executing these little fish
I’d sterilize before getting more fish. It’s not your fault, you’re buying fish bringing in the disease already. Go with another source of goldfish imo.
How do I remove the parasites that are there on my goldfishes ? Will they get removed by themselves ?
You can use tweezers to remove them manually, then kill the eggs with medication.
Can minnfinn do the job? Or must use cyromazine to get rid of the eggs left in the tank and filter? Last time I only used tweezer to pull out the worms but didn’t use any medication to treat the whole tank and about a week later they’re back again and worse than the before. Please advise what to do thanks
MinnFinn can work on Anchor Worm. I believe the cyro is a bit faster to work on it though.
I noticed 3 of my goldfish in my pond has anchor worm. I managed to use tweezer to temove on 1 of the fish. I purchased the microbe lift anchor worm to treat. Im on day 3 of 1st treatment. Will the anchor worms just die and fall off the fish? How long till it does that?
I recommend tweezing off the adults if you can, it helps reduce the infection faster, relying on the treatment more to kill the eggs.
If I don’t manually remove the anchor worm, about how long will it take for it to die and fall off? The medication says to treat over the course of 3 weeks. We are in the first week and I’m wondering if it is working.
I recommend removing them manually in conjunction with the medication as the medication only works on eggs, so the adults will continue to stress the fish.
Hello! I just wanted to let you know that your blog is amazing. I followed your article on Ich this past week and have done water changes 2 times a day, for 3/4 days and followed with medicine and a .5 % salinity of the water for each change, and the Ich is gone already not even 10 days later! I couldn’t be more thrilled.
I noticed a bump on the back of my goldfish but there was nothing poking out of it. When I initially researched I thought it was cancer. So I left the poor guy alone. ? Last night I noticed the bump I first saw was gone, but he had two more on his side with little brown sticks poking out. Your helpful article made me realize it was anchor worms so I pulled them out and ordered some of the Microbe Lice and Anchor worm treatment from Amazon.
Thank you so much for helping keep my little Buster alive. I’ve had him for about 5 years now and all of his friends (including a goldfish I won from a carnival 9 years ago) died in January from an overly enthusiastic tank cleaning that killed good bacteria.
Sorry for the long winded post, but thank you so much for this wonderful blog! Definitely gonna keep coming back for anything and everything!
Your feedback made me so happy Valerie, glad to hear the blog is helping you and Buster!
Hi Meredith, I have a 7 year old Comet goldfish that I suspect has anchor worm. There is a tiny splinter sticking out but it is short and does not look like a worm with the anchor end. I tried to remove this splinter but it was hard to see it, the scales were in the way, and my Comet is a squirmer. Do you have any advise for how to manually remove the anchor worm (assuming it is one)? Thank you for all the useful information on your website. Water is testing fine, my Comet is working through some fin rot, and something has seemed off the past month but it\’s been hard to diagnose until seeing the splinter.
Where is it located on the fish? Has the fish been exposed to other fish recently, or come from a pond? Tweezers are the best way to manually remove them.
Located on the back third of his body above the anal fin. Not super close to the fun though. He has been alone , no contact with a pond or other fish. I did bring in a few plants from a fish store before I started noticing different behavior. Fish in the tank with the plants at the store looked healthy. Plants were rinsed well, not quarantine. I’m having a hard time seeing the splinter protrusion now as the scale is loose.
Ah, the new plants could have brought it in.
Hi again, The \”splinter\” on his side is no longer there. However, with the torn fins (though they do not seem to be getting worse) and the every few days odd behavior it seems something is wrong. Would you medicate in this case to be sure? I\’m considering MinnFinn but am concerned about the cost of the beneficial bacteria. Also, wondering if I should do one treatment with the bio wheels running. Thanks for your help. I\’m curious what you would do in this case.
I\’ve also noticed tiny squiggly worms from time to time in the tank and after I rinse the Marineland filter catridges. Thank you for your time!
The squiggly worms are harmless detritus worms. I would definitely medicate. The beneficial bacteria can be replenished with ATM Colony and just watch your water quality closely after treatment, performing water changes as needed.
Thank you. Would you recommend MinnFinn, Herbtana, or something else in this case? I\’ve only medicated with melafix and salt in the past so am medicine shy. Thanks again.
I would either use MinnFinn (natural treatment) or the Microbe-Lift Lice/Anchor worm myself. Herbtana is probably not going to cut it in this case.
Hi, Can I run my UV sterilizer (green machine) while treating the tank with Microbe-Lift Lice/Anchor worm? Thank you
I would recommend checking with the manufacturer on that one. I would think it should be fine.
Hello Meredith, can microbe lift kills the eggs inside the filter and deep inside the media ? if it is so then it must kills all the beneficial bacteria in the filter too right?
To my knowledge it does not harm the bacteria, it is an agent against the eggs.
Recently set up my tank again after 7/8 years of no use. Bought 3 fish from PetsMart 3 weeks ago, one died last week and I thought it was from bullying (they were constantly nipping at that one) but today I noticed my fantail had 3 lice on it. I’m NEVER buying fish from a big box store again. The same thing happened when I bought a fish years ago and it infected the whole tank fish I had for years prior without a problem (they all ended up dying in the end), so I recognised the lice instantly. Thanks for all this helpful advice, I hope I can turn the situation around this time. Unfortunetly I don’t believe Petsmart will treat the fish as they said they will when I called earlier today, I’m sure they’ll just destroy them which makes me very sad. But I’m going to bring the there and hope for the best
Yikes. Sorry to hear that. Hopefully you can fix them up.