it has what looks like a pimple on the spine of its tail and two sacks that look like bubbles of air on its one gill. it behaves normally, eating and swimming fine. the pimple I noticed today, the sacs on its gills have been getting bigger for a few days now. at first they were hard to see, looked like just a discoloration. now they are definitely full of fluid. about the diameter of a pinhead. I will try to take a picture but my camera doesn't take very good close up shots through the glass. they always come out blurry.