MANUAL OF FISH-CULTURE. 89 



Adult fish are very liable to be affected with fungus, which generally 

 appears after a bruise or hurt, or when the fish are in an emaciated 

 condition. If the trouble results from an injury, it can often be cured 

 before it spreads to the sound flesh, but if fungus spreads like a slimy 

 web all over the fish, it is fatal. Fish must be handled very carefully 

 during the spawning season to prevent scarifying the body in any way, 

 as they are esi)ecially susceptible to fungus at that period. Should it 

 occur, the fish must be caught at once, rubbed with salt on the affected 

 j)art, and then released in a pond or tank by itself, where it can be 

 caught for further treatment in a day or two, while those affected all 

 over the body should be killed and thrown out at once. 



"Glassy eggs" may be the result of overretention of the eggs on the 

 part of the parent fish. If the eggs are not delivered within a reason- 

 able length of time, say from 3G to 48 hours after they fall from the 

 ovaries into the abdomen, they are surrounded with a thin watery fluid, 

 having a glassy appearance, which if allowed to come in contact with 

 water will change to a milky white, and the eggs absorbing this fluid 

 become hard and " glassy," after which fecundation is impossible. 

 Many thousand eggs have been lost annually on tbis account, and many 

 brood fish lost or rendered worthless from the same cause. The fish in 

 captivity will not sj)awn of their own accord unless they have access 

 to gravel or earth in which to make nests. If attention is not given to 

 the spawning fish and their eggs taken when ripe, they soon become 

 very dark in color, the abdomen swells, and sometimes the head will 

 enlarge, causing the eyes to protrude. Under these conditions the fish 

 will die in a few days, but with free and easy access to the raceway 

 they will not often be thus affected. 



