accompanies aging. Often it is a mixture of bacterial and other infections brought about by organically rich (dirty) water. The water conditions cripple the fish's immune system and it can't keep out the bacterial bloom. Many of these bacteria, like many of the parasites, which can afflict our fish, are in the water "at a non-lethal level" much of the time. When we (or the pet shop if he is a recent purchase) fall behind in our tank maintenance, the fish get sick.
The critters working away cause the fish to be unable to control their body fluids. That liquid gathers in the cells (and under the skin?) causing the skin to rise/swell. That in turn causes the scales to stand up.
If you had isolated your male when it first looked "iffy", given it much cleaner water and treated with a broad spectrum antibiotic (treatment elsewhere so you don't trash the nitrogen cycle in your aquarium), there is a remote chance you could have reversed the process. :(
If I were you, I would do 40-45% partial water changes on that tank (assuming that you have saved and treated enough "seasoned" water of roughly the same temperature) a couple of times in the next week. I might also take out any really dark filter floss and rinse it until it is merely grayish. (If you rinse it until it is white, you washed all of the beneficial bacteria away with the dirt!)
A lot of time people and even I have left the afflicted fish in a covered bowl on top of the tank, so that that fish can continue in quarantine. Placing it upon the tank cover usually keeps the bowl at about the aquarium's temperature, if you use glass tops on tanks.)
If the male guppy is really suffering, I would go to Immediate Help and check out euthanasia. Personally, if I can find the clove oil, I might put him in water with the prescribed amount of that. Guppies otherwise pretty much go "to sleep" in the freezer.
Ah, the clove oil, purchased at a Walgreen drug store, is in such a tiny container, it gets lost on my remedy shelf. I did indeed find it - probably because I don't need it at the moment. ;)
Corydoras and other more hyper fish do not do well in cooling water. So don't try that with a terminally ill Cory.
For more on dropsy and the viewpoint of others, look up dropsy in Immediate Help.
One of the grand old men of the killifish hobby and someone I would like to think of as a mentor, George Maier, owner of a Mom and Pop shop on the north side of Chicago in the old German-American neighborhood along Belmont Street, Halsted and Irving Park Road, suggested that regular weekly, partial water changes, after quarantining new purchases, would eliminate 90-some per cent of all fish diseases.
If the fish are well, there is no way to prove that. ;) But the fish in George's shop (even the feeders) and those he brought to club meetings from his fishroom, seemed always in great health.
Good luck! I think that you will be able to keep your other guppies from coming down with dropsy.
Immediate Help
