106 TJ. S. BUREAU OF FISHERIES. 



necessary to distribute a portion of the product before this stage is 

 reached in order to prevent overcrowding. The basses, bream, and 

 other pond fishes are distributed from three weeks to several months 

 after they are hatched. The last lots of bass shipped usually range 

 from 4 to 6 and the sunfish from 2 to 4 inches in length. The com- 

 mercial species, such as whitefish, trout, cod, pike, perch, etc., which 

 are hatched in large numbers, are necessarily planted as fry. The 

 basses, sunfishcs, crappie, yellow perch, and other fishes rescued from 

 the landlocked ponds and pools in the Mississippi Valley are from 

 3 to 6 inches in length when distributed. Eggs are distributed to 

 State hatcheries and occasionally to applicants with the understand- 

 ing that the resultant fry are to be planted in public waters. 



PERIOD OF DISTRIBUTION. 



Because of the increased cost of shipping fish, trips to distant 

 points are postponed until there are a sufficient number of applica- 

 tions to warrant the expense. The bureau does not carry a stock of 

 fish for delivery on demand, and when the supply of one year becomes 

 exhausted it is necessary to wait until the next year's product is avail- 

 able to meet requests. The distribution of trout in the Eastern States 

 is arranged early in March, and requests for trout submitted after 

 March 1 are carried over until the following year. In the Rocky 

 Mountain regions trout are distributed during the period extending 

 from May to October, and applications should be filed with the 

 bureau not later than May 1. Black bass, sunfish, crappie, etc., are 

 supplied from May to November, and requests for those species 

 should be filed prior to May 1, in order to receive attention before 

 the following winter. It is the aim of the bureau to fill applications 

 in the order of their receipt and to make delivery as soon thereafter 

 as possible. 



AERATION or WATER. 



When a large number of fish are confined in a receptacle, they 

 soon consume the gaseous oxygen dissolved in the water, especially 

 if the vessel is allowed to stand a while. It is important, therefore, 

 that applicants receiving fish plant them as soon as possible. AVhen 

 the fish are carried in a vehicle, the splashing of the water serves to 

 renew the supply of oxygen. This is true only when travel is over 

 rough roads. Fish manifest their desire for oxygen by coming to 

 the surface of the water. The water must be aerated, and a dipper 

 should be provided for this purpose. Sufficient aeration may be 

 accomplished by dipping the water and letting it fall from a height 

 of about 2 feet, this process being repeated when the fish show 

 signs of distress. Fish should not he allotted to remain on the depot 

 platforms, and, uiithout expert knowledge in handling live fsh, no 

 attempt should he made to hold them, overnight. 



Cool temperature is an important factor in holding fish, as the 

 cooler the water the more gaseous oxygen it holds in solution. 

 The proper temperature may be maintained by wrapping the con- 

 tainers in wet sacking or by placing ice in the cans. 



