74 XORTHERX FISHES 



Figure 3. Paddlefish, Polyodon spat hula. 



Evermann in Kentucky. Forbes in Illinois, and Alexander in Louisiana 

 all agree that during the spawning season the paddlefish move in large 

 schools near the surface. Little has been known about their growth 

 rate; although many people have thought that the rate was slow, it 

 may be quite fast. Dr. R. E. Johnson of the Minnesota Department 

 of Conservation writes that a paddlefish kept in a pond by the Nebras- 

 ka Game, Forestation and Parks Commission grew at a rate of nearly 

 a foot a year. 



Paddlefish live in waters with a muddy bottom. As they swim 

 through the water, the snout weaves back and forth giving the im- 

 pression of a spirallike movement. They feed largely on minute Crus- 

 tacea, which they secure by swimming with their mouths open. The 

 Crustacea are strained from the water by means of long, fine gill-rakers, 

 which form very efficient plankton nets. The stomachs examined by 

 Eddy and Simer (19*29) were usually filled with minute water fleas 

 and copepods. Occasionally they may sweep up a few small aquatic 

 insects. 



This species originally ranged in the quiet waters of the Mississippi 

 and larger tributaries and bayous from Minneapolis to the Gulf. At 

 present it is much more abundant in the southern part of its range. 

 Only a few specimens of this species are taken annually from Lake St. 

 Croix and from the Mississippi River below Lake Pepin. They were 

 at one time rather abundant in Lake Pepin, and their almost complete 

 disappearance from these waters within the past twenty years is at- 

 tributed by the commercial fishermen to the Keokuk Dam. Wasteful 

 methods of fishing, mainly for the purpose of procuring the eggs, may 

 partly account for their disappearance. Pollution of the Mississippi, 

 particularly at the head of Lake Pepin, may have been a contributing 

 cause. Paddlefish formerly occurred in the Minnesota River as far up 

 as Mankato and in the St. Croix River to Taylors Falls. 



The paddlefish are caught largely in nets and traps, but they have 

 been caught occasionally on setlines. The flesh has an ever-increasing 

 commercial value, for it is almost boneless and closely resembles that of 

 the rock sturgeon in flavor and texture. In some southern localities it 

 commands a high price and is sold as "boneless cat." Part of its value 

 lies in the eggs, which are sometimes mixed with those of the sturgeon 

 to produce caviar of excellent quality. 



