52 



REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



Fish Lakes, Washington, D. C. (Rudolph Hessel, Superintendent). 



During the summer 43,844 black bass were removed from the breed- 

 ing-ponds to retaining-tanks. Of these 32,967 were carried through 

 the summer in the rearing-pools and distributed in October and Novem- 

 ber, when they varied in size from 3 to 6 inches. The large loss of 

 young fish is attributed to some extent to their being held for several 

 weeks in the retaining-tanks, at which time the water was constantly 

 roiled. In one of the smaller ponds 200 small-mouth bass were 

 reared and distributed with the large-mouth bass during the fall. 

 During the winter the west pond, which covered an area of 6^ acres, 

 and which had been devoted for a number of years to the rearing of 

 shad, was divided by means of a partition (397 feet long) into two 

 ponds, one to be devoted to the rearing of bass and the other to shad. 



In April the adult black bass were placed as usual in the partitions 

 in the north and south ponds and in that part of the west pond 

 devoted to their culture, but owing to the low temperature prevailing 

 in the spring months they did not commence spawning until about 

 the middle of May. A number of nests were observed about the 20th 

 and one pair spawned on the night of May 23 in the Eagle Pond, 

 where an excellent opportunity for watching the development of the 

 eggs was afforded. On May 25 the dark spots indicating the eyes 

 were conspicuous, and on the fourth day the fry burst from the shell. 

 The}^ seemed to lie motionless at the bottom of the nest until the 29th, 

 when they rose a few inches in the water but did not leave the nest 

 until the following day, when they began to take on a darker color. 

 Another nest in the south pond was first noted on the 25tli. Two 

 days afterwards the first fry appeared, and by the 28th the entire brood 

 was hatched. They remained on the nest until June 1, when they 

 commenced to rise in a similar manner to those observed on the first 

 nest. A number of other nests were noticed on the 26th and 29th of 

 May, and it was observed that the eggs remained 4 to 4^ days before 

 they hatched, the fry rising from the nests 3 to 5 days later. The 

 period of incubation depends on the temperature of tlie water. 



A series of temperatures taken at 7 o'(;lock in the evening from 

 May 23 to June 2 was as follows, the mean being 73° : 



Date. 



May 23 

 May 24 

 May 25 

 May 26 

 May 27 

 May 28 



Temp. 



op 



74' 



73 



70 

 67 

 73 



72 



Date. 



May 29 

 May 30 

 May 31 

 June 1 . 

 June 2 . 



Temp. 



70* 



72 

 76 



81 



77 



As soon as the spawning season was over the adults were removed 

 from the spawning partitions and the young were allowed to pass into 

 the main body of the pond, which had been thoroughly stocked with 



