black moor fish

Question
We have a black moor fish in a 20 gallon tank.  We have 5 other fish in the tank with him including a very large 26 cent goldfish, an algae eater, 2 daneo's and an albino catfish.  Our black moor has been swimming upside down for some time now (2 months) and now he has a big spot on his belly.  Acting normal and eating just fine.  the spot looks like a blister.  What is wrong with him?????   HELP!!!!!

Answer
Hi Teresa:  he probably has a swim-bladder disease or infection.  Try to feed him a couple of frozen peas (thaw them first) or you can try to not feed him for a day or so... you need to add aquarium salt to the water... watch the spot and see if it goes away...  you can try a parasitical med... keep me posted... dave