XV -EXPERIMEiNTS UPON RETARDING THE DEVELOPMENT OF 

 EGGS OF THE SHAD, MADE IN 1879, AT THE UNITED STATES 

 SHAD-HATCHING STATION AT HAVRE DE GRACE, MD. 



By H. J. Rice, Sc. D. 



The report hereby submitted j?ives somewhat iu detail the methods and 

 results of the experiments in retarding the development of impregnated 

 shad-spawn which were carried on by Mr. F. IST. Clark and myself dur- 

 ing themouth of June, 1879, attheUnited States Fish Commission barges, 

 near Havre de Grace, Md. These investigations were instituted princi- 

 pally for the purpose of ascertaining the possibility and practicability 

 of transporting shad-spawn across the ocean, with a view to introduc- 

 ing American fish into European waters, and all of our efforts were 

 made with that end in view. Normally, as is well known, or as is gener- 

 ally considered at the present time, shad-spawn requires for its develop- 

 ment a constant although slight motion, and a continuous exchange of 

 fresh water. Under these conditions, whether produced naturally or 

 artificially, the spawn after impregnation will proceed iu its develop- 

 ment, and the young shad come to maturity, quickly or slowly accord- 

 ing to the temperature of the water in which they are placed. With a 

 temperature of 68° to 74° the ova will hatch out in from three to five 

 days. If the water is of a lower temperature, or about 56°, the develop- 

 ment will be much prolonged and the hatching take place in about 

 eleven days. Upon an ocean voyage the great difficulty to be sur- 

 mounted would be the lack of fresh water. Motion can be given to the 

 eggs, and the temperature can be kept at any point which may be desired 

 by means of ice, but all the water used with the eggs must be such as 

 can be taken on board at the beginning of the trip. 



The questions to be answered, then, in regard to a shipment of the kind 

 proposed were, "Can shad ova be carried, and will they go on in their 

 development, in stagnant water, or in water which, although changed 

 as often as thought necessary, is not absolutely fresh ; or can they 

 be carried in some other manner, as for instance in an ice-chest, as is 

 done with some other kinds of fish-spawn, as that of the white-fish of 

 the Great Lakes for example"?" It is quite evident that if it could be 

 shown to be jjossible, even with considerable care, to carry shad-ova 

 in either of these ways, it would not be very difficult to transport any 

 quantity which might be desired to the other side of the Atlantic, and 



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