73 



Figure 18. 



— An inexpensive fish 

 distribution tank. 



dissolved oxygen for the duration of the trip under 

 full load. 



d. When the trip is unusually long and the weather 

 extremely hot, the temperature should be maintained 

 between 65° and 70° F. by periodic icing. When pos- 

 sible, long hauls should be made on cool days. Tanks 

 that are constantly used for long hauls should be 

 insulated with 4 inches of cork. 



e. Salt is a tonic for fish and can be used to 

 help them over the rigors of transportation. A salt 

 bath should be given after the trip. When the aeration 

 equipment consists of a pump and water jets, salt should 

 not be used in the tank because sodium chloride rusts 

 the equipment. 



OPERATION OP THE HOLDING TANK 



The loss of minnows from handling and holding 

 operations is most evident in the holding tank. Though 

 much of the loss is attributed to fungus disease, the 

 largest partis the direct result of rough handling and 

 careless operation of the holding tank. The following 

 suggestions will help eliminate this mortality. 



a. Holding tanks should be constructed of wood or 

 smooth concrete and painted heavily, with asphaltum 

 paint. Smooth sides in the tank help prevent disease 

 and injury to the fish. The tank should be deep enough 

 so that the fish are not injured by the jets of water 



