52 



U. S. BUREAU OF TISHERIES. 



Table 2. — Kind of food fed and amount required for 1,000 rainboio trout of 



various sizes. 



PREPARING EGGS FOR SHIPMENT. 



Trout eggs are in condition to bear transportation when they have 

 developed sufficiently to show the eyespots but are not too old to reach 

 their destination before the time for hatching. Allowance is made 

 for changes in temperature on the road that would cause them to 

 hatch too soon. Best results are obtained by selecting eggs after they 

 have reached the "tender" stage, or when the eyespots are first dis- 

 cernible by holding the egg up to the light. Twenty-four hours in 

 advance of shipment the eggs selected are transferred from the trays 

 to pans or buckets. They are thoroughly washed with a stream of 

 water of sufficient force to cause some agitation among them or by 

 stirring them with a feather brush. This treatment not only removes 

 all sediment from the eggs but causes all infertile eggs, which up to 

 this time may have retained the color of good ones, to turn white and 

 thus facilitates their removal. Unless this is done infertile eggs are 

 very likely to get into the shipment. The eggs are then accurately 

 weighed or measured (1 ounce may be weighed and counted or the 

 eggs for one tray counted and then weighed), and the total number 

 needed may be estimated from the result thus obtained. 



To facilitate the work of packing the trays are sometimes placed 

 in a trough in which there is no current of water and the eggs poured 

 on them from the graduate or measure. The trays are then shaken 

 gently to settle the eggs evenly into place. If trough room is not 

 available, a tub of water may be used. All trays and moss should be 

 soaked in cold water for several hours previous to use, and when dry 

 moss is used it is well to expose it to frost. If this is not practicable, 

 shaved ice may be sprinkled through it. It is also desirable that the 

 packing be done in a room with a low temperature. 



PACKING EGGS FOR SHIPMENT. 



The method of packing trout eggs on deep trays with a cushion of 

 wet sphagnum moss over each tray is no longer practiced to any great 

 extent with rainbow trout. The egg tray now in use has a cheese- 

 cloth or linen scrim bottom, it is about three-sixteenths of an inch 

 thick, has a depth varying with the diameter of the eggs to be shipped, 

 and has such other dimensions as may be required. For shipping 

 50,000 eggs 25 trays are used ; for 100^000 eggs 33 trays, and so on, 



