2l6 



TWELFTH ANNUAL REPORT OF THE 



This disease was never observed in the creeks until four or five years 

 ago. ■ It lasts until freezing weather sets in and affects all kinds of small 

 fish, but is never seen in large fish. Mr. Scriba has never noticed it in a 

 pike perch exceeding five inches in length. The disease conies very sud- 

 denly and destroys the eyes in three or four days. The region in which 

 this disorder appears seems to be limited in Scriba creek, from its mouth to 

 the Southwell Mill dam. Frederick creek as far as the hatchery dam has 

 it also, but in neither of the creeks does it occur above the dams, fish of all 

 kinds in the upper waters being free of it. 



Mr. Marsh wrote as follows on the subject: " I examined the eyes care- 

 fully but found no parasite save bacteria, which were not conclusive, as they 

 should be present in such degenerations whatever the primary cause. The 



X 



%i 



SMALL-MOUTHED BLACK BASS 



eyes contained considerable clotted blood * * * . The internal organs 

 were much shrunken and some of the fish emaciated and there is probably 

 a general infection, bacterial or protozoan, of which the eye disease is a 

 part. We are much indebted to you for the specimens and for opening 

 such an interesting subject and apparently a new one." 



Black Bass. 



The Commission receives from time to time specimens of fish contain- 

 ing parasites or affected by some disease causing disfigurement, or death. 

 From the office of the Forest and Stream Publishing Co. a small-mouthed 

 black bass, caught in Culver lake, New Jersey, in June, 1905, was received 

 for examination and report, and it was found that all of the viscera of this 



