74 



REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



loss from cannibalism was large. Late in July the ponds were drawn 

 and the fry placed in troughs, where they were fed on live maggots. 

 Though large numbers of them' died on account of weakness and 

 insufficient nourishment while in the ponds, their improvement after 

 being transferred to the troughs was marked. As an article of food 

 the maggots proved far superior to anything ever used at this station. 

 They remain alive a long time after being placed in the water, thereby 

 attracting the notice of the young bass, which snap them up greedily. 

 It is believed they will also prove a most economical food, as they 

 can be produced in large quantities from the refuse of livers, at little 

 cost. As a result of the work with this fish, 4,300 were distributed 

 in the fall and 200 were held for brood stock. 



The rock-bass work has not been as successful as was anticipated, 

 due to low temperature of water and lack of natural food in the ponds. 

 The construction of a new pond will permit the extension of this work, 

 and it is believed that large numbers can be reared in the future. 



At the close of the year there were on hand the following fish : 



Species. 



Calendar year in which fish were hatched. 



1900. 



1899. 



1898. 



1897. 



1896. 



Brook trout .. •.. - 



30,800 



15,500 



5,000 



3,000 



1,810 







500 



Rainbow trout . 



3,600 



834 





1,340 



Grayling _ 









Loch Leven trout . 





16 





Black bass - 







140 



Rock bass 











58 















Total -- 



54,300 



1,810 



4,434 



16 



3,038 







Investigations made during the spring of 1899 indicated that large 

 numbers of fish could be collected in the vicinity of Bellevue, Iowa, 

 from the overflowed lands of the Mississippi River, as it is the center 

 of a vast territory extending on the Illinois side of the river from 

 Galena to a point 22 miles south, and on the Iowa side from Dubuque 

 to the mouth of the Maquoketa River. Bellevue was also selected on 

 account of the good railroad facilities and its excellent water supply. 

 The preparatory work of fitting up a small temporary station was 

 commenced on July 14 and completed on the 25th. The equipment 

 consisted of four wooden retaining-tanks, 12 feet by 4 feet by 3 feet, 

 set up on the levee in front of the city, the city council having granted 

 permission to use the ground free of charge. The tanks were sup- 

 plied with T^^ater from the city works through a half-inch galvanized-iron 

 pipe, under pressure of 100 pounds, and escaped into the tank through 

 a one-fourth-inch pet-cock, which reduced the volume but caused 

 it to fiow into the tank with great force, taking with it large quantities 

 of air. The average number of gallons of water used in each tank 

 per day was 2,000. This water was furnished at a cost of 10 cents per 

 1,000 gallons. A light wooden frame was constructed above the 

 tanks, over which was stretched a canvas cover to protect the fish 

 from strong sunlight. The daily collections were held in these tanks 



