Losses of eggs are caused by frost, hail, and other physical agencies as already noted, but are 

 due chiefly to fungus (Saprolegnia). Sometimes, owing to peculiar local conditions, many eggs 

 become attacked by this troublesome growth and occasionally every egg in a given pond may be affected 

 and killed unless proper measures are taken. The fungus does not ordinarily begin to develop on 

 healthy eggs, but first attacks unfertilized or dead eggs and spreads thence to adjoining sound eggs. 

 If affected eggs are removed as soon as noticed, the spread of the parasite may be checked and no 

 great damage done; but if the water of a pond is thickly charged with the fungus spores and there is 

 indication of a general infection, the healthy eggs should be removed to another pond filled with 

 pure water, and the contaminated pond should be treated with sodium chloride, copper sulphate, or 

 other fungicides, then drawn down and thoroughly cleansed. 



Fungus attacks likewise young and adult fish, especially those with lowered vitality or with an 

 abraded surface on which the spores may lodge, and eventually destroys if unchecked. When the char- 

 acteristic white fuzzy growth appears, the healthy fish should be transferred to another pond, the 

 diseased fish should be segregated in a tank or basin, and the infected pond should be drawn down 

 and the bottom and sides thoroughly disinfected and dried. If the disease has not progressed too far 

 the fish may be cured by the local application of a solution of common salt or peroxide of hydrogen, or 

 by immersion in a moderately strong salt solution for a few seconds at a time or until the fish shows 

 signs of suffering. The local use of other common antiseptics and fungicides (boracic acid, salicylic 

 acid, formalin, carbolic acid, permanganate of potassium, etc.) in proper strength will naturally be 

 suggested. Fungous disease is responsible for a large percentage of the mortality among goldfish, 

 and should therefore be carefully studied by breeders and fanciers. 



Crustacean parasites are common on goldfish as on all other fresh-water fishes. They are usually 



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