478 U. S. BUREAU OF FISHERIES 



should be left upon the eggs. The eggs must be well stirred with 

 the inflowing water. 



There need be no fear of applying too much milt. The amount 

 obtained from one fish may be ample for the eggs from two, but it is 

 always better to employ two males, Egt^s may look promisiiigf or two 

 or three hours, yet never expand to full size or produce fish. They lie 

 at the bottom underneath any good ones that may be in the pan; 

 they stick to the fingers, while the good ones will not, nor can they 

 be successfull}^ removed from hatching jars until after several days. 

 Unskilled spawn takers are liable to the mistake of stripping eggs 

 without having the necessary milt to impregnate them, for several 

 spaw^lers may be taken over a period of 10 or 20 minutes without 

 the capture of a male fish. In such cases (of great frequency late in 

 the season) the female fish must be placed conveniently, backs down, 

 to prevent the eggs from running out, and the males may have to be 

 obtained from other boats. When ripe shad are taken in seines two 

 or three large baskets should be in readiness to receive them. 



Good eggs are transparent and so soft and light that they are not 

 apparent to the touch when the fingers are moved among them. 

 When the temperature is about 70*^ no change is observed for about 

 12 or 13 minutes after the milt is added, but about this time a careful 

 movement of the fingers in the pan discloses their presence, and in a 

 httle more than 20 minutes from the time the milt is applied they 

 feel like shot against the fingers and to an experienced eye are 

 observed to increase slightly in size; when a day old they will not 

 break if dropped to the floor. In transferring the eggs to other 

 vessels the rim of the smaller pan should be gently immersed beneath 

 the water surface in the larger one and the pouring take place grad- 

 ually. To prev^ent splashing in boats, a small pan should be put on 

 the water surface of the larger pan. Sudden jars must be avoided, 

 all foreign substances excluded, and the pans be free from grease and 

 salt. After the application of milt they expand to full size in 20 to 

 60 minutes, depending partly on temperature, and at this stage they 

 may be doubled up in the larger pans, the cpiestion of safety in moving 

 them being determined by their hardness. 



If the eggs have absorbed sufficient water in the spawn pan, they 

 swell and adhere to each other, forming a compact mass, and are 

 ready to be transferred to the hatching jars, but if they are not sufli- 

 ciently expanded or '' water-hardened " they must remain in the pans, 

 from 30 to 60 minutes being required for their full expansion. 



In transfen'ing the eggs to the hatcliin^ jars a small screen is 

 placed over the throat of the egg funnel mentioned on page 482, which 

 serves to remove any fish scales or other foreign matter that may 

 have become mixed with the eggs. 



HATCHERY AND EQUIPMENT 



The building intended solely for a shad hatchery need not be of 

 elaborate construction, since it will be used for only a short period of 

 time during the year, but ample space, light, ventilation, and arrange- 

 ments for moderate heating are essential. At the Bj-yans Point 

 hatchery the water supply is obtained from the Potomac River, being 

 delivered through steam pumps to elevated tanks, from which it is 

 distributed to the hatchery. During periods when only a small 



