72 



thermometer should be used to determine temperature 

 di f ferences. 



Minnows that are to be used locally should not be 

 held in very cold water. Unless the fisherman travels 

 far enough for the water to warm up, the minnows will 

 turn belly up when placed in the warm lake water. 



TRANSPORTING MINNOWS 



The hauling of minnows over long distances during 

 very hot weather presents a difficult problem. Success 

 depends on close adherence to sound methods. The 

 following list includes some important requirements. 



a. Conditions such as crowding, excessive handling 

 and changing water temperatures encountered when 

 transporting minnows for long distances, often prove 

 fatal to many of the fish. As a means of reducing this 

 loss, a 24-hour "hardening" process has been practiced. 

 The fish to be transported are collected and placed into 

 a tank where the water temperature can gradually be 

 reduced until it is between 50° and 60° F. The fish 

 are left in this bath for about 24 hours for condition- 

 ing. At the end of this period, they are transferred 

 to transporting tanks that contain water of the same 

 temperature and are ready for moving. People whc use 

 this technique claim that the fish will not only stand 

 the trip better but will tolerate more handling and 

 crowding than before. 



b. To prevent injury to the fish, the wooden 

 sides of the tank should be smooth. The tank should 

 be large enough so that on rough roads the fish will 

 not be dashed against the sides. Several sizes of 

 tanks have proved satisfactory. One popular type is a 

 single-compartment tank, 4 feet square and 3 feet deep, 

 aerated with oxygen dispersed through a perforated 

 release tube. This tank will caj-ry 125 pounds of 

 minnows for 300 or 400 miles with little or no loss. 

 Another successful tank is 6 feet long, 3 feet wide, 

 and 25 feet deep. This tank is divided into two com- 

 partments, each of which will hold 100 pounds of 

 minnows. It has the advantage of permitting the dealer 

 to sort his fish either by species or by size when 

 necessary (fig. 18). 



c. Carrying tanks must be well aerated either by 

 the application of oxygen or by pumping the water 

 through pressure jets. Any system used should be able 

 to maintain a minimum of three parts per million of 



