A patchy greyish-white “beat up” look on the body with some spider-webbing and a roughened appearance is indicative of an infestation by a microscopic external protozoan parasite such as Chilodonella or Costia (Ichthyobodo).
This is oftentimes difficult to differentiate from bullying. The patchiness is typically rather diffuse as opposed to the more well-defined white spots caused by ramming during aggression. And there is typically some excess mucus evident in chilodonella and costia.
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In severe cases these protozoan diseases can give so called “slime coat disease” where the mucous on the scales of a fish is literally sloughing off. These fish need a so called “shotgun approach” with both ich and fluke medications in the water and broad spectrum antibiotics in the food. This is covered in this link:
11.13. Slime Coat Disease
There are a whole series of protozoan diseases which can present themselves exactly like chilodonella and costia. These diseases include trichodina and tetrahymena. Occasionally epistylis will present just like this. The fact that the diseases are different is only found when microscope smears are taken of the skin. Treatment of all these diseases is similar:
- Add a formalin/malachite green medication (Ich-X, Rid-Ich Plus, Blue Planet White Spot Remedy and Mardel QuickCure) or a Copper based medication (Cupramine, Copper Power, Copper Aide or Copper Safe) to the water of the aquarium to kill the free swimming organisms.
- Add lots of additional biofiltration (under-gravel, canister or sump) to filter out and thus kill the free swimming organisms. This added biofiltration also reduces the bacterial loading in the water which in turn allows the fish to devote more immune system resources to the pathogen.
- Do not put the fish in a hospital/quarantine tank
- Do not change out or clean the filter media.
- Do not raise the temperature of the tank
- Add a 24/7 UV sterilizer to kill the free swimming organisms and reduce the bacterial loading in the water which in turn allows the fish to devote more immune system resources to the pathogen.
- Added aeration always is helpful
These treatments will typically work for both chilodonella and costia.
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Anon says
Hi Vicky,
I am having the same exact issue, literally no other symptoms apart from they seem to prefer less hard food now, so no pellets.
I also asked a vet and bought a microscope myself, the vet initially found Trichodina but said it was in the normal expected numbers…. despite that I’ve actually treated for Trichodina and found absolutely nothing on several different species of fish since, but still they flash continuously.
My cyprinids are worst affected, the loaches barely show any symptoms at all, and this is why I am in this situation in the first place. Having bought loaches as my very first fish from my LFS, I had no idea anything was wrong. They occasionally scratched, but as soon as I put cyprinids in there I could tell immediately that the loaches had something.
Since going back to LFS I noticed they put the same species of cyprinid into the tank where I bought my loaches, and guess what? All are flashing…
I don’t believe it is bacterial as I have moved my cyprinids to an isolation tank to treat them. It’s basically a sterile environment and it’s been nearly 3 weeks. They are still flashing, maybe not as often… so far I have treated with Praziquantel, Flubendazole and Sera Protazol… and just this week I’ve added some salt to aid them.
My only theories are that it could be highly resistant flukes, there are people who say you can’t always find flukes unless you take gill biopsies from both sides, and even then they could be hiding. I don’t know how true any of this is but my fish flash both their heads and their sides/bellies. Whatever is irritating them is all over, yet I can’t find anything when I take slime coat samples. I use a microscope with magnification up to 1000x and I have checked all magnifications from 40x – 400x on both live and dead fish (one of my fish died due to unrelated accident in isolation tank).
I have spent months reading and scouring the internet, talking to people and I don’t seem to be any wiser. I just suspect it’s a parasite, especially having seen the fishes’ behaviours at LFS.
ps. my tank is a river tank with extremely high flow. It gets large weekly water changes and there is simply nowhere for mulm to settle.
Dave says
In reply to Vicki … First off it doesn’t sound like Costia. Ich X and copper are both very effective against costia (Metronidazole is NOT effective). I’m going to go with hypoxic conditions somewhere in the tank giving some semi-toxic organic poisons out. I would do several large (75% to 90%) water changes after several deep vacuums of the substrate. Hunt for dark colored (dark brown or black) mulm somewhere in the tank, possibly under a rock. Dark colored mulm indicates oxygen poor conditions which can give out some irritating chemicals that cause flashing. They typically do not kill the fish. The presence of dark mulm indicates overfeeding, protein poor food, poor water circulation and/or poor aeration.
Vicki Mitchell says
My fish have been chronically flashing for months. They are eating normally with the exception of 2 which are not. I have called out a fish vet to diagnose the problem 2x in the last 9 months with no results. Microscopic slides have revealed nothing. I am currently treating with coppersafe. The vet wants to treat with metronidazole. She’s thinking they might have ichthyobodo (Costia) but I have not before read about that helping Costia. I raised the temperature in the tank to 83 because I have read it can’t reproduce at that temperature. I am at a loss as to what’s wrong with my fish. My parameters are as follows, ph 7.6, NO1 0, NO2 0, NO3 40-80ppm. She said sometimes the protozoan isn’t always visible under the microscope. She suggested sacrificing a fish for a skin biopsy. Maybe you have an idea? Something someone is missing? I’ve treated with Ich X, praziquantel, copper and other various meds with no success. I’m at a loss. These are African cichlids in your typical all male show tank. 180 gallons with roughly 40ish fish. Thank you
Vicki