Name This Fish Illness

[KittyKat]

Feeding only medicated food could have caused the problem, as it is not intended for long term use. That also encourages whatever it medicates against to adapt and become immune to the medication.

I was asking about aeration because it is possible for fish to swallow bubbles from a venturi or air stone, but that usually causes swim bladder problems as well.

Does the bubble cause the shape of the fish to change? Which part of the body? Does it look empty or full?

Another option is that it can be some by-product of the stress caused by the male: a single male can stress a single female to death, which is why for small numbers of livebearers 2-3 females per male is recommended.

 

[MollyFresh]

No i only did that after they have had issues. And The air is recent to, i promise you nothing im doing now caused the problem, no one has yet to tell me wat it actually is either which bothers me. The bubble causes bloating, it looks full, it is in the stomach area. And The male is fairly new so it hasn't been stressed that long which is another reason why i bought the other female she should be fine it happens less often. thank you.

 

[loraxchick]

Id suspect the bloom is from stirring the substrate up either by removing the plants or waterchanges if you've started those. Internal parasite foid does not cause resistance like antibiotics does. Over the course of dozens of generations of the parasite but not from even the lifetime of the fish. Bacteria have much quicker generation times and are almost genetically programmed to mutate quickly.
shame you can't get a picture. Would be very helpful. Any boyancy problems? Is the fish spitting out its food or refusing to eat?
for now I agree with above to get the med mix out of the tank. Easily done by running fresh carbon in the tank for 24-48 hours. Or just keep diluting with waterchanges. Epsom salts are helpful for bloating issues if due to fluid buildup and will help with constipation. Id also cut back on feeding, perhaps skipping a day in between and see if it helps if a constipating issue.
doubtful the plants or rocks started this. There are always nasties in the water or affecting our fish. A healthy non- stressed fish' s immune system can fight them off. Id get more plants or more hideys to limit any harrassment, and also help with water chemistry.
all I got for now.
best of luck.
Cheers