TROPICAL AQUAEIUM FISHES 147 



cessful treatment. 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 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 becomes sud- 

 denly blood-red, the color sometimes extending to the body immediately 

 adjoining. If allowed to continue this form of the disease is rapidly dis- 

 astrous. 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, particularly 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 the 

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



Fig. 97. Fish Affected With White Fungus 

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

 and drawn together and the general appearance is one of listlessness. 



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 sufifocation. The latter 

 stage is not always reached, the fish often becoming so emaciated as to die 

 in the second stage of the malady. The bacteria causing this disease are 

 present in virtually all water, but can make no inroads on a fish in good 

 condition, A weakened fish once infected will breed so many bacteria that 



