140 NORTHERN FISHES 



the attention of carnivorous fishes from the young of the larger species, 

 upon which, without them, the adults of these larger species would fall 

 with the full force of their voracious appetities. By offering themselves, 

 no doubt as unconscious, but sufficient, substitutes, they thus help to 

 preserve — for their own future destruction, however, be it noticed — the 

 young of many species which would otherwise be forced to feed on each 

 other's progeny. It is not too much to say, consequently, that the num- 

 ber of game fishes which any waters can maintain is largely conditioned 

 upon its permanent stock of minnows." 



Faced with such facts we should take steps to control and supple- 

 ment, where possible, nature's effort to preserve a proper balance of 

 game and forage fishes. At present there are hundreds of bait-minnow 

 dealers scattered over the northern states, and their entire stock in trade 

 is procured from public waters, in nearly every instance at the expense 

 of game fishes. Several years ago certain streams and lakes in Minnesota 

 had to be closed entirely to the taking of minnows for commercial pur- 

 poses, and conditions have now reached an acute stage in which the 

 natural food supply is so reduced as to curtail the game fish capacity of 

 certain lakes and streams. Minnows have sometimes been hauled over 

 200 miles in an effort to supply the demand for live bait. When some 

 dealer, without boasting, advises you that he has marketed over 100,000 

 dozen minnows in a single season, the magnitude of the industry and 

 its effect upon fish life are manifest. And this is not the worst of it by 

 any means, for it is safe to assert that for every minnow marketed by 

 the dealer at least five others have been destroyed, either through 

 careless handling when seined or assorted, in the course of transporta- 

 tion to the dealer's holding vats, or through improper facilities for the 

 care of the minnows at the place of sale. 



Some species of this family have played an important economic role 

 besides that of being bait and food for other fishes, for many larger 

 species, such as the carp, are important food fishes, particularly in the 

 Old World. Some of the important European species of this family are 

 the tench, roach, bleak, and bream. The crystalline, silvery coloring 

 matter of various cyprinids is said to have been employed for ornamental 

 purposes by the Chinese from time immemorial. The important arti- 

 ficial pearl industry has been carried on in France and Germany with 

 the scales of the bleak. 



In the following descriptions very little attempt is made to describe 

 in detail the different species, but their ranges so far as shown by collec- 

 tions and records are indicated. 



Key to Common Species of Family CYPRINIDAE* 



1. Dorsal fin with a long base and more than 11 soft fin rays; dorsal and anal 

 fins eacli with a strong spinous ray ? 



^Adapted from Hubbs and Lagler, 1941. 



