Black smudge

[knight7453]

I have a gold fish that has been in my pond for a few months and it has developed black smudge disease and an ulcer on its side.
I have always been under the impression that this condition develops when the ammonia level is too high.
My test kit shows PH around 6.5 and ammonia around .5 ppm as and the color chart shows the water in a safe level.
Non of the other fish seem to be suffering this condition so my question is: what else can cause black smudge disease in goldfish?

[Pa Nancy]

It could be what's called  MELANOPHORE MIGRATION" - It's caused by *any* chemical or traumatic irritant or injury on the surface of the fishes' bodies.

I have a goldie with this right now also. She was banged around pretty good during spawning. I seem to have a goldie or two that has it every year. After a couple weeks it goes away.

Here's a small article I found on it.

http://www.koivet.com/koivet/index.php?option=com_content&view=article&id=45:blackening-koi-or-goldfish-skin&catid=39:koi-conditions&Itemid=61

If your fish has an ulcer than your water isn't up to par. And a PH of 6. 5 is too low for goldies. You can raise it by adding a little bit of baking soda. I'm  no expert and I don't have the formula  for it. I'm sure that website  I gave you will have it. But you must FIRST take care of the ammonia. By raising the PH you also raise the toxicity of ammonia. A few water changes will help to bring that ammonia down. You also need to test for KH that controls your PH and is very important. A too low of PH will burn your fish and may be the reason why it has the spot. Why no others have it?  No idea.
GOOD LUCK!

[knight7453]

Thanks for the info Nancy.
The fish I have in isolation isn t doing much better and I just got back from having my water tested and have been told that this may be an isolated incident with this fish.
I will have more info tomorrow and let you know what treatment is recommended.
Thank you for your help

[Julles]

Wow, I never heard of that before.