VI— DISEASES AND FATALITIES OF EGGS AND FISH 



[HE high degree of domestication to which the Japanese goldfish have been brought 

 predisposes to various maladies and fatalities from which the wild fish are for the most 

 part free. The diseases of goldfish are due to bacteria, to animal and vegetable para- 

 sites, to improper food and feeding, and to physical causes, and are such as afifect 

 fresh- water fishes generally. The nature of some diseases of goldfish in Japan is not 

 full}'^ understood because not as yet investigated in a scientific way, and the treatment is largely 

 empirical. While this subject is very important, it need not now be noticed at great length; and it 

 will suffice for present purposes to mention some of the more common maladies, and to give the 

 experience and views of Japanese goldfish culturists. 



Under ordinary conditions only about 30 per cent of the eggs laid result in fish that survive long 

 enough to reach a marketable size. The losses are 40 per cent during incubation and 30 per cent in 

 the fry and fingerling stages. 



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