COMMON FISHES OF MISSISSIPPI RIVER 
195 
As regards Lake Keokuk, the conditions are quite different from those just de- 
scribed. Even had the trees and brush been cleared away, there are great areas 
sufficiently shallow and constant enough in depth to permit of the growth of sub- 
merged plants that afford the necessary shelter for minnows and other small fish. In 
giving special attention to other fishes we have made no adequate observations on 
minnows in the lake. As will appear later, two species constitute the chief minnow 
fauna of the river below the dam. 
Carp. Cyprinus carpio Linnsous 
“german” carp 
Despite a widespread prejudice against the carp, it remains one of the most 
valuable food fishes of the United States. According to statistical reports, the value 
of the carp product exceeds that of any other of the river fishes. 
More than two-thirds of the carp product of the United States comes from the 
Mississippi Basin, and of this share about one-third is from the Illinois River and more 
than half from the Mississippi River itself and its minor tributaries. (See statistics 
in Sette, 1925.) Thus, in 1922, 9,374,073 pounds of carp were obtained from the 
Mississippi River itself and such tributaries as were not sufficiently significant to be 
named separately. 
The question of the relation of carp to other fishes is one upon which so many 
opinions have been held and so much has been written that it would be superfluous 
for us to enter into a discussion of the matter, especially as we have no original con- 
tribution to make to the subject. We accept the carp as it is, standing with the 
buffalo fishes as paramount commercial fishes of the river. 
The carp, which is supposed to have originated in Asia and which was intro- 
duced into this country from Germany, is perhaps the most adaptable of all fishes. 
It is found in the far south and is an important fish of the Great Lakes, especially of 
Lake Erie. It thrives and reproduces in rivers, lakes, and small ponds, and is, there- 
fore, evidently without the need for extensive migrations for purposes of breeding. 
It is hardly necessary to ask whether the dam as an obstruction is injurious to such a 
fish, but the pool, with its enlarged water area, might be supposed to promote the 
multiplication of carp. 
