40 



REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



There were 146,000 retained at the station for hatching and rearing; 

 the balance were lost owing to lack of fertilization. From the eggs 

 retained at the station, 118,978 fry were hatched, 110,000 of which were 

 lost in the hatchery and 98,112 counted out into the pools for rearing. 

 At the close of the fiscal year there remained on hand 84,012. 



The following table shows in detail the eggs lost in incubation, the fry 

 lost in the hatching-house, and the number placed in the rearing-pools : 



Eggs retained. 



a 5,000 of this lot were delivered at the hatchery aa fry. 



In view of the desirability of increasing the output of rainbow trout, 

 arrangements were made with Mrs. M. B. Murrell, of Little Eock, Ark., 

 for the Commission to collect eggs from the Mammoth Springs (Ark.) 

 fish ponds on shares. Mr. Neill, an employee of I^eosho Station, was 

 detailed for this i)urpose and conducted the work under the direction 

 of the superintendent. Only 73,000 eggs were obtained from the 104 

 females handled, 31,000 of which were shipped to Duluth. The balance 

 were turned over to Mrs. Murrell. On May 12 a case containing 12,590 

 rainbow-trout eggs was received from the California Fish Commission. 

 They commenced hatching immediately and finished May 19. The fry 

 began to take food on May 26, when only two weeks old. On June 8 

 there reuiained on hand 9,925 of these fish. They will be retained at 

 the hatchery and reared as brood stock. 



Brooh trout. — On December 8, 1894, a consignment of 20,000 brook- 

 trout eggs was received from Leadville Station. The eggs commenced 

 hatching on December 13 and finished December 21. They appeared 

 to do well until April 10, when an epidemic, described by Livingston 

 Stone as black-gill fever, made its appearance. From that time until 

 the close of the year the death rate was very heavy, and by the end of 

 June only 829 remained. Dissections and microscopic examinations 

 were made. Every organ was normal except the gills, which presented 

 a dark pasty appearance, like the lungs of an animal dead from pneu- 

 monia. A feature of the disease was its quick action; a fish would 

 appear in perfect health and be dead in five minutes. The temperature 

 of the water could not be changed, and the other remedies in general 

 use, salt and muck, would obviously have aggravated the trouble. 



