February, 1943 
individuals as large as 10.5 inches, and 
many were from 8.5 to 10.0 inches. The 
smallest fish taken was 4.5 inches long. 
A few of the planted yearling bass were 
caught and identified by their clipped dor- 
sal fin. These had grown from less than 
BENNETT: MANAGEMENT OF ARTIFICIAL LAKES 
375 
populations, such as frequently occur in 
small glacial lakes, have been observed. 
This difterence is probably due to a great- 
er variety and abundance of foods, other 
than fish, that are available. 
2. A lake containing only bass should 
Fig. 7.—Bluegills from a new farm pond built by the U. S. Soil Conservation Service in 
Adams County, Ill. These fish averaged 0.10 pound when stocked in June of 1939 and 0.72 
pound when recaptured, July, 1940. By 1941 this bluegill population had become badly stunted, 
because of overpopulation resulting from natural spawn. No more large bluegills such as these 
will be produced in this pond until the population is properly thinned. 
7 inches at the time of their introduction, 
to between 11.5 and 12.5 inches by Octo- 
ber. | 
‘Two other experimental lakes, one con- 
taining bass and one bass and Gambusia 
affinis (Baird & Girard), are being 
studied. Neither has been followed long 
enough to give much pertinent informa- 
tion. However, several inferences based 
on. studies of bass populations in other 
lakes seem to favor the use of this fish 
alone or in combination with some min- 
now of small size: 
1. Stunting (4 or 5 years to reach 
legal length) in bass is apparently rare 
in Illinois artificial lakes, as no stunted 
maintain a larger population of these fish 
than was found in most lakes inhabited by 
mixed populations. In the lake census 
work the largest bass population found 
averaged 58 pounds per acre and this 
represented only 14.8 per cent of the total 
fish population (see tables 1 and 2). 
3. A single brood of bass may show 
a great deal of variation in the size of 
individual fish shortly after the brood be- 
comes scattered. The fact that smaller 
individuals are eaten by the larger fish of 
the same brood partially eliminates the 
danger of dominant slow-growing broods 
of bass. 
4. Although bass fry and fingerlings 
