292 



IT. S. BUREAU OF FISHERIES 



oxygen cylinder. Hundreds of large fresh-water fishes have been 

 brought in by the same method. A shipment of marine fishes was 

 made recently from the New York Aquarium to San Francisco — a 

 four-day journey by rail — with small loss.* In this case the speci- 

 mens were in charge of a messenger. G. Friedrichs has used oxygen 

 very successfully in transporting large numbers of food fishes to the 

 New York markets. The admission of oxj^gen into the water must 

 be controlled carefully by valves, as it is under high pressure. 



Fig. 30. — Shipping crato with jars containing oxygen 

 FEEDING 



The feeding of a large collection of fishes is a matter involving 

 no small amount of labor and expense. Formerly, when the collec- 

 tions in the New York Aquarium were fed daily, one attendant de- 

 voted about half of each clay to the preparation of the food. Equally 

 good results are secured now by feeding every other day, and the 

 labor is lessened. Usually, there are about 5,000 fishes of all sizes 

 in the tanks. The food consists of fish, clams, and meats, which 

 are sliced, chopped, or minced, as may be necessary to suit the size 

 of the specimens. The whole collection is fed carefully in order 

 • that there may not be food left unconsumed, which would have to 

 be removed to prevent its affecting the water supply. Most of the food 

 used in an aquarium is obtained in the markets and consists largely 

 of food fishes such as cod and herring. Preference naturallv is 



* Bulletin, New York Zoological Society, May-June, 1927. 



