GOITRE AMONG TROUT, AND EFFORTS TO 

 ERADICATE IT 



By W. E. Meehan 



About the middle of February, 1908, the advanced trout 

 fry in the hatchery at Spruce Greek, Pa., began to exhibit 

 signs of uneasiness. Their movements were erratic and 

 they took food languidly. The troughs were heavily 

 laden with fish, with a flow of about three gallons of water 

 a minute through each. In a few days it was evident that 

 all the young trout, numbering about '2,000,000, were 

 seriously sick, for they began to die in large numbers. 



An examination showed the throat to be inflamed, and 

 this was seemingly the immediate cause of death. At the 

 time the disease was not considered necessarily fatal, be- 

 cause on transferring several thousand affected fish to out- 

 side ponds, the inflammation disappeared and most of them 

 apparently recovered. Belief that the disease was not 

 malignant was strengthened when it developed that ad- 

 vanced fry transferred to streams were later reported to 

 have done well. There was also an almost immediate de- 

 crease in trouble after the troughs had been thinned. The 

 cause of the disease was therefore thought to be over- 

 crowding. 



In the month of March following, when the trout had 

 reached the size of no. 1 fingerlings, the disease appeared 

 again, although not in as severe a form. There were less 

 fish in each trough, but the same quantity of water was run- 

 ning through the troughs. On increasing the water supply 

 by about half a gallon a minute, there quickly followed an 

 improvement in the condition of the trout. Under the same 

 conditions there was no recurrence, either in 1910 or 1911. 

 in the hatching house. 



Late in the fall of 1909, fungus suddenly developed 

 among the two and three year old trout in the ponds, and it 

 quickly spread among the yearlings. At least 20,000 fish 



