ontem morreume um peixe mais ou menos assim... uma colisa femea.. tinha a barriga inchada..e andava sempre no fundo do aquário.. eu vi kk coisa parecido na wikipédia vela se é mais ou menos isto:
This disease is characterised by a swollen or hollow abdomen (Ascites). A concentration of fluid in the body tissues and cavities causes the fish's abdomen to become swollen and appear bloated. Swollen areas may exhibit a 'pine-cone' appearance caused by the fishes scales sticking out. You can best see this by viewing your fish from the top. Fish may also stop feeding, appear off-colour, become listless and/or lethargic, have sunken eyes, and hang at the top or stay at the bottom of the aquarium.
The condition affects the fish's internal organs, ceasing proper function.
Gouramies, Cyprinids (barbs, danios, etc), guppies, betta and goldfish are prone to this disease.
Dropsy is fairly easy to diagnose non-specifically, however, it is much harder to diagnose the cause. The main cause is bacterial infection. The causative agent may be introduced through food or dirty water. Edema second to kidney failure or ascites due to liver or heart failure are other possible causes.
deve ter haver com isso.. é dificil de curar e de achar uma causa possivel :S