Symptoms of Ammonia poisoning

[shergill00]

I have couple of zebra danios but there seems to be some problem with this guy. Its somewhat bloated at one place and swims slowly as compared to others. Cannot seem to find what the problem.

Let me know what is this and remedy to prevent and cure it.

After going through net i think the symptoms looks like ammonia poisoning. But i am surprised as i am changing water after every 3 days about 20%. Bio load is also not high, have 10 danios, 10 danceas, 2 mollies and 4 horadandios. Tank is 24x15x18 with diy substrate.

[deepesh]

Not ammonia poisoning for sure. A localized bulge like this... First thought should be a tumor, distant second is a localised infection. I would go with tumor and see how it evolves. If it grows rapidly I would euthanize. If it does not grow at all I would wait and watch. By the way at this size I would regard any observable growth as rapid growth.

[VishaalDalal]

similar Pimple appeared on one of my newly acquired CPD fry but the next day it had burst and now only a little redness remains. though on a small fish it looks very big.

the point is whether this is a localized boil or is it any parasite.