FISH DISEASES 153 



water will be all that is necessary if taken in time. Two grains of 

 permanganate of potash to the gallon of water is a successfur treat- 

 ment for goldfishes, but is dangerous to tropicals. It is best to use 

 this in an enamel or a glass receptacle. Organic substances, such as 

 wood or floating particles of dirt, quickly decompose the chemical. 

 The fish may be given the permanganate treatment several hours at 

 a time, but a fresh solution should be made daily. 



An entirely different kind of fin congestion is sometimes prevalent 

 in the fall, especially when the fishes are first taken in, young fishes 

 being more liable to attacks. The base of the tail and other fins be- 

 comes suddenly blood-red, the color sometimes extending to the body 

 immediately adjoining. If allowed to continue, this form of the dis- 

 ease is rapidly disastrous. Fortunately, it yields with surprising 

 quickness to either salt water or permanganate of potash treatment. 

 When alternatives to salt-water treatment are suggested, the fancier 

 will certainly be on the safe side by giving the salt the first trial, par- 

 ticularl}' if carefully followed out as we have directed. 



White Fungus. This is next to the most common disease among 

 goldfishes, and is responsible for the majority of deaths, except among 

 very young fry. It begins on the tail and other fins, extending over 



Fig. 149. Fish Affected With White Fungus 

 This illustration is characteristic of sick fishes in general. The fins are col- 

 lapsed and the general appearance is one of listlessness. 



the body and into the gills. When it reaches this stage it is usually 

 fatal. The progress of the disease is marked by the development of a 

 white scum which destroys the fins, prevents the natural functions of 

 the skin, and when the parasite enters the gills causes death by suf- 

 focation. The latter stage is not always reached, the fish often becom- 

 ing so emaciated as to die in the second stage of the malady. The 

 fungi causing this disease are present in virtually all water, but can 



