Red dot on young and baby lampeyes

[confused_aquarist]

Infections in the brain can be from bacteria, protozoans or viruses, most commonly protozoan.

Do you happen to know if the protozoan infections can be treated with metronidazole?

 

[Colin_T]

Do you happen to know if the protozoan infections can be treated with metronidazole?

Once the protozoan infection has caused damage to the fish there is not normally anything that cures it and the fish die. Adding salt to the tank after cleaning the tank up (big water change, gravel clean substrate, clean filter) will usually stop it spreading to other fish.

Metronidazole might help but I have never used it to treat infections in the brain. I use Metronidazole for intestinal infections and it works well on them.

 

[Colin_T]

I see. That is actually what I thought, they are too young to be so ill from fish TB. But, I don't think it's a coincidence for multiple disease to appear one by one, I think it's the same disease.

I will try to dissect the fish if it cannot be rescued (though I am not a fan), maybe it can be protozoan or microsporidia.
I have no plant in the tank, it's a breeder box, the plants in the main tank are all tissue culture.

I'm sure it's the same problem/ disease affecting the babies (not the one by itself in quarantine but the others) because it has the same symptom (red spot, albeit in different places). Is there any chance you can borrow someone's camera and get decent pictures?

It's not a microsporidian infection because that causes the muscle tissue to turn a cream/ white colour over the course of a month or so and the fish lose condition and die.

I don't know of any protozoan infections that cause a red spot. In really bad external protozoan infections caused by Chilodonella, Costia or, Trichodina, the area around the edge of the infection can go red from blood but the infection appears as a cream, white or grey patch/es on the body. The fish also rub on objects when they have an external protozoan infection.

Most internal protozoan infections occur in the digestive tract or the brain (different types of protozoa affect the intestine compared to the brain).
Intestinal protozoan infections cause fish to go off their food, lose weight rapidly, do a stringy white poop, and die within a week or two of showing these symptoms.

Protozoan and other types of infections in the brain cause the fish to lose balance and they randomly spiral through the water instead of swimming normally. Depending on the colour of the fish you can sometimes see a pink colour under the skin around the head and face of the affected fish. This can appear on one side of the fish or throughout the entire head area.

 

[confused_aquarist]

I'm sure it's the same problem/ disease affecting the babies (not the one by itself in quarantine but the others) because it has the same symptom (red spot, albeit in different places). Is there any chance you can borrow someone's camera and get decent pictures?

I think I'll clean the tank if another fish shows with head symptoms. So far I don't see any motor issues like spiraling but I do see tiny pink dots in the brain of the affected fish and looking from the top there is clearly a tiny red dot.

As for the camera, the red spots all disappeared now so probably I will take a picture if it affects a different fry. It's definitely occurring less often because probably all of them have had it now.

 

[confused_aquarist]

Update:
Kan+doxy double treatment did not work at all, fry loses appetite and swims less. May be too late but trying with metro.

 

[confused_aquarist]

Update: A day later after metro the fry had to euthanized because it was not eating and suffering a lot. Gross view didn't show any external parasites, and brain tissue did not contain motile protozoan or worm. But I cannot tell apart immotile parasite from debris or brain cell. Another fry appeared 2 days later with the same symptoms and brain bleed. I euthanized because there was no treatment available and to prevent further spread. So far red spots have not appeared for a long time (will update if it appears again) and also brain injuries haven't occurred, so I will leave as is.

I had also consulted experts from the pet shop. Based on the bleeding on/under skin it was concluded this was a case of bacterial or viral septicemia but not likely due to lampeye iridovirus because death occurs more slowly and is more prevalent with captive bred fish. I believe it can be a mild case of lampeye iridovirus due to shop contamination with captive water, but wild specimen can deal with the disease more effectively or differently.