754 



BULLETIN OF THE BUREAU OF FISHERIES. 



Number of Fishes of Given Kinds and Sizes to be Transported in a io-Gallon Can under 



Average Conditions — Continued. 



Note. — The varying usage in the classification of young fish as to size has caused such confusion 

 and difficulty that the Bureau has adopted uniform definitions, as follows: 



Fry=fish up to the time the yolk sac is absorbed and feeding begins. 



Advanced fry — fish from the end of the fry period until they have reached a length of i inch. 



Fjn(7t'r/:'n(7.y = fish between the length of i inch and the yearling stage, the various sizes to be desig- 

 nated as follows: No. i, a fish i inch in length and up to 2 inches; no. 2, a fish 2 inches in length and 

 up to 3 inches; no. 3, a fish 3 inches in length and up to 4 inches, etc. 



Yearlings =fish that are i year old, but less than 2 years old from the date of hatching, these may 

 be designated no. i, no. 2, no. 3, etc., after the plan prescribed for fingerlings. 



In the care of fish away from the air circulation of the cars, aeration is 

 . usually accomplished by the use of a long-handled dipper, and this method for 

 10 or 15 cans, which is the usual number handled by detached messengers, if 

 energetically operated has no equal. Several forms of aerating devices have 

 their good points, their use is permitted, and efforts are being made to improve 

 upon the present methods of hand aeration in order to lighten the labors of the 

 messengers, who not infrequently care for the fish for two or three days before 

 they arrive at a destination. 



For aeration in cans containing small fry, such as the shad, pike perch, 

 white perch, yellow perch, and whitefish, it is customary to siphon a portion of 

 the water into a pail (the head of the siphon being in a wire cage covered with 

 cheese cloth), aerate it with a dipper, add ice to temper it if necessary, and then 

 pour it back through a large funnel which reaches nearly to the bottom of the 

 can, the lower part of the funnel for about 6 inches being made of perforated 

 tin to break the force of the water. On short trips little, if any, aeration is 

 necessar}'. 



Cans holding the larger fry and young fish may be aerated by dipping the 

 water up and pouring it back again from a height of 15 or 20 inches. When 

 transportation is by water it is customary to renew the water in the cans en route 

 instead of resorting to hand aeration. With fishes of the Salmonidae family, 

 ice may be placed directly in the water in the cans. 



