952 BULLETIN OF THE BUREAU OF FISHERIES. 



but perhaps even some disadvantage. Micropterus, which bring a higher price, 

 have disappeared, as have also the river perch and the pike, probably on account 

 of a lack of small fishes for food. The tench and the roach (Leuciscus erythro- 

 phtalmus) are the only ones that remain. 



How to provide new food is the present difficult problem, which, after the 

 failure with the sunfish, will scarcely find easy solution with present experience. 



PLANTS IN LAKE VARANO. 



Area of this lake, 360 hectares; greatest depth, 7 meters; much plankton, 

 very rich vegetation; maximum temperature of the water, 24° C. at the surface, 

 24° C. at the bottom; minimum temperature, 0° C. at the surface, 6° C. at the 

 bottom. 



The species of fish contained in the lake are, in the order of their abundance, 

 sunfish, river perch, tench, bleak, black bass, eel, zander, mirror carp, and pike. 

 The sunfish and black bass, also the zander and the carp, were introduced in 

 this lake. 



The results obtained with the American fishes here are marvelous, especially 

 with the sunfish, as two other lakes communicating with Lake Varano are over- 

 stocked with sunfish. It is scarcely possible to notice any effect on the other 

 kinds of fishes, except that the pike has grown scarcer and the bleak has 

 disappeared. The river perch is much fatter and grows much more rapidly 

 than before. 



The plants of introduced fishes, together with subsequent catches, are shown 



in tables vi and vii. The yearly output of fish of all kinds, amounting, formerly 



to 170 tons, has increased to 300 and more tons. Table viii gives the total 



catch for 1907, which is exceedingly good, amounting to almost 90 kilograms per 



hectare. 



Table VL — Sunfish (Lepomis .-^ukitus). 



[Eighty-three 3 -year old brood fishes introduced in 1900.] 



Year. 



1901- 

 1902- 

 1903- 

 1904- 

 190S- 

 1906. 

 1907- 



Total. 



Weight of 

 catch. 



Kilograms . 

 682. s 

 I,9I9S 

 5.845-9 

 5.958.4 

 7.456.9 

 5.990.7 

 12, 8x1. 4 



40.665.3 



