Treatment for Fish Lice That's Safe For Scaleless Fish?

[Akeath]

I have what I believe is fish lice in my aquarium on my Honey Gourami just above his eye - close enough to the eye I don't dare remove it manually. I already tried General Cure a couple weeks ago, but the fish lice seem to be immune to it. Apparently that's not uncommon with fish lice, and Potassium Permanganate seems to be one of the only sure shots to kill these.

I'm wondering if I could put some Potassium Permanganate such as Jungle Clear Water in the aquarium to try and kill any other fish lice that might be there without hurting my beloved Longfin Albino Bristlenose Pleco or my Sterbai Corycats. I would also do a twice strength external dip for the Honey Gourami, but I'd like to treat the rest of the tank because I've lost multiple fish to this and I want to make sure to eradicate all the fish lice.

[bekateen]

Potassium permanganate (KMnO4) is particularly harsh. Besides all else, it will kill your biological filtration, and you will need to cycle the tank again.

On the positive side, lice tend to be pretty obvious, so dipping the infected fish may be sufficient. That said, it is may be necessary to treat the tank.

Myself, I've had nothing but bad experiences with potassium permanganate, so I think it's good that your other fish are C. sterbai and longfin albino BNs. I say this not because they will certainly survive the therapy, but because they are "relatively" available to replace in case they die. Neither species is so rare that you won't find it in the USA if they die.

I know that's not optimistic language, but it's based on my real-life experiences that KMnO4 has killed every fish I've ever treated. So I think of it as a "nuclear option" to cleanse the tank, knowing I'll possibly have to replace the fish.

Personally, I'd start with the isolation/dip and not treat the tank, then see if the lice reappear.

Best of luck,
Eric

[TwoTankAmin]

If you are willing to try a bath, then this might interest you:

Interestingly, salt (plain old sodium chloride), which is often overlooked in favor of other drugs and chemicals that are often thought to be better and more powerful, is one safe and very effective method of treating ich, as well as many other external parasites. Salt is the number one best chemical to manage fish health. For most purposes, uniodized table salt is adequate, although there is nothing wrong with using aquarium salt specifically sold for that purpose, such as sea salt, solar salt, salt sold for consumption by livestock and Kosher salt. As an aid to osmoregulation, salt may be added in a concentration of 2-3 ppt (or 0.02-0.03 parts per million: ppm). This concentration is safe for most fish, and at this concentration, protozoa cannot live with this level of salinity. This is approximately one tenth the strength of seawater.

As a treatment for ich and some other protozoa, the infested fish should be dipped in salt water at 30 ppt (or 3.0 ppm, which is the salinity of seawater), for 30 seconds up to several minutes, or until the fish rolls on its side. At that time, the fish should be placed back in its normal salinity water. To mix this solution, use tank water and dissolve in 30 teaspoons of salt per gallon, then place the fish into this water, monitoring it the entire time. This is then repeated once daily for three treatments, with a 30-70 % tank water change between treatments. This treatment is different from most of the others, in that it is used to treat the organisms in the skin of the fish, and not the free-living stages found in the fish tank. Lower doses may be used as a continuous bath in the fish tank. At 5-10 ppt (0.5-1.0 ppm), fish can survive for several hours to several days, and this will effectively kill the ich organisms. At 4-5 ppt (0.4-0.5 ppm), freshwater fish can live for up to four weeks, and this will also break the ich life cycle. A bath of 4-5 ppt will effectively kill anchorworms and lice. It must be noted that a salinity of 5 ppt or greater will usually kill live plants. One ppt= 1 tsp/gallon, three ppt=1 tbsp/gallon. One pound/100 gallon pond water.

(Underline and Bold added by me.)
from http://www.oscarfishlover.com/tropical-fish-parasites

[Jobro]

JBL Aradol Plus 250 works good against argulus. As always I don't know if it is available in the US.

It's based on Diflubenzuron .

It stops the argulus from growing new "skin" so they die during molting. Also affects shrimps and other crustaceans. Snails showed no signs of problem though. And it is safe for Plecos. I had to use it some times. Repeated use for 2-3 times (each after 3 weeks) is recommended to make sure no fry survives.

[dw1305]

Hi all,

...... As an aid to osmoregulation, salt may be added in a concentration of 2-3 ppt (or 0.02-0.03 parts per million: ppm). This concentration is safe for most fish, and at this concentration, protozoa cannot live with this level of salinity. This is approximately one tenth the strength of seawater...... A bath of 4-5 ppt will effectively kill anchorworms and lice. It must be noted that a salinity of 5 ppt or greater will usually kill live plants. One ppt= 1 tsp/gallon, three ppt=1 tbsp/gallon. One pound/100 gallon pond water..... from http://www.oscarfishlover.com/tropical-fish-parasites

That is the other way around with the powers of 10, ppt (parts per thousand) are 10^-3 and ppm are 10^-6, so 2-3 ppt is 2000 - 3000 ppm.

I've never tried salt baths (fortunately I've never needed to), but I'm definitely not a fan of therapeutic salt addition for soft water fish (partially because I'm a planted tank keeper). A high level of chloride ions (Cl-) will provide some protection against poisoning by nitrite (NO2-), but this is a drop in the ocean compared to the advantages of healthy growing plants in maintaining water quality.

You also have the conductivity issue, 3000 ppm of NaCl adds about 5000 microS of extra electrical conductivity.

These fish have evolved in water where the conductivity values are in the 10 - 100's range, and the Na+ and Cl- ions concentrations are vanishingly small, why would a salt addition be therapeutic?

cheers Darrel

[Lycosid]

These fish have evolved in water where the conductivity values are in the 10 - 100's range, and the Na+ and Cl- ions concentrations are vanishingly small, why would a salt addition be therapeutic?

General "therapeutic" use aside, the square-cube rule would make me think that salinity would be much harder on small freshwater external parasites than larger freshwater fish. It would be bad for everyone, but possibly fatal for parasites and uncomfortable for fish.

[dw1305]

Hi all,

General "therapeutic" use aside, the square-cube rule would make me think that salinity would be much harder on small freshwater external parasites than larger freshwater fish. It would be bad for everyone, but possibly fatal for parasites and uncomfortable for fish.

You may well be right. I would imagine that there may be a "rule of thumb" based upon which taxonomic grouping that a parasite belongs to?

I know that some sucessful keepers (and businesses) use salt addition as a routine process, but I struggle to find a rationale for it, unless you are keeping brackish water fish.

cheers Darrel

[Lycosid]

Hi all,

General "therapeutic" use aside, the square-cube rule would make me think that salinity would be much harder on small freshwater external parasites than larger freshwater fish. It would be bad for everyone, but possibly fatal for parasites and uncomfortable for fish.

You may well be right. I would imagine that there may be a "rule of thumb" based upon which taxonomic grouping that a parasite belongs to?

Fish lice have a relatively impermeable cuticle, which helps them survive osmotic change, but are probably "osmoregulating" by remaining isotonic to their surroundings. (Other maxillipods are known to do this.) So then the question is what happens when their insides get salty.

I know that some sucessful keepers (and businesses) use salt addition as a routine process, but I struggle to find a rationale for it, unless you are keeping brackish water fish.

I agree with this fully. Often the rationale offered fails to explain things because of basic biological errors.

[Viktor Jarikov]

I used salt at 0.5%-1% as an in-tank, long term bath and that didn't affect anchor worms (I realize this is about lice but this is the closest experience of mine with a parasitic crustacean.) Dimilin-X (the above mentioned dibenzfuron) most definitely kills them and is said to be gentle on most fish, certainly such was my experience.