808 



UNITED STATES, FISH-CULTUKE IN THE. 



Artificial Impregnation of Shad-Eggs, After the shad 

 are taken from the gill-nets or seines, they should 

 be examined to see if the eggs and milt will flow out 

 freely when gentle pressure is made upon the belly. 



If the process of taking eggs or milt is continued 

 too long, traces of blood will appear. After impreg- 

 nation, the eggs should be kept either in pans or on 

 trays ; if in the former, they must be filled with wa- 

 ter, which should be changed every hour or oftener. 

 In pouring water into the pans, always let it fall on 

 the side. The eggs must be preserved from shock's 



SHAD (Clupea sapidissima). 



of all kinds. When trays are used, the bottom 01 

 the tray should be covered with a wet flannel cloth, 

 and the eggs must not be more than two layers deep. 

 The apparatus used by the United States Fish Com- 

 mission for the transportation of eggs is McDonald's 

 egg-transportation crate, described above. This crate 

 marks the beginning of the dry transportation of shad- 

 eggs. 



The spawning-pans used by the commission are 

 made of " marble ized iron," which will not rust in 

 salt-water. 



The period of incubation of all fish-eggs varies with 

 the temperature of the water. I cpuote from the " Ee- 

 port of the United States Commissioner of Fish and 

 Fisheries," Part II, p. 430, the record of observations 

 made by Mr. J. W. Milner: "In the shad-eggs the 

 period required for the release of the fish from the 

 eggs was, with an average temperature of 64, though 

 actually varying between 62 and 68, about seven 

 days. With an average temperature of 65, actually 

 between 62 and 69, the time was about six days. 

 With an average temperature of nearly 66, actually 

 between 62 and 69, the time for the most of the fish 

 to be free was about five days. 

 An average of 68, between 

 60 and 75, released them in 

 about three days. An average 

 of 72, really between 65 and 

 80, released the fish in about 

 seventy hours, the shortest 

 time observed for a large 

 quantity of eggs, though usu- 

 ally some were hatched a few 

 hours before the ma.iority, and 

 a few eggs lingered for several 

 hours after the eclosion of the 

 rest." A newly-hatched shad 

 is a little less than half an inch 

 long. The yolk-sac is ab- 

 sorbed in four or five days 

 after hatching. Glass vessels 

 are the best for hatching pur- 

 poses ; the Chase, the Clark, 

 and the McDonald jars pos- 

 sess great advantages over 



all forms of metallic apparatus, the principal being 

 their prevention of the formation of fungus, by 

 the continuous movement which they insure, and 

 the facility for removing dead eggs. Embryo shad 

 are transported in cans of block -tin, resembling 

 milk-cans. The style extensively used by the United 

 States Fish Commission is cylindrical, with a con- 



tracted top and a cover. The usual dimensions are: 

 height, 24 inches, diameter, 14 inches. This can will 

 accommodate from 5,000 to 20,000 embryos^ depend- 

 ing on the distance to be traveled and the time occu- 

 pied in transit. Until recently it was supposed to be 

 necessary to change the water at least once in two 

 hours. Now it is known that a change every four or 

 six hours will generally give better results. Young 

 shad have been kept alive and deposited in streams 

 after a journey lasting 184 hours ; they have been kcpc 

 alive even as long as 240 hours by Messrs. Mather 

 and Anderson in the at- 

 tempt to carry them to 

 Germany. 



Carp-Cmlture. The carp is 

 said to have been intro- 

 duced into Europe from 

 Central Asia many cen- 

 turies ago. It is now com- 

 mon in most of the large 

 European rivers, and has 

 become extensively domes- 

 ticated in Bohemia, Aus- 

 tria, Germany, and 1 ranee. 

 From Europe the carp was 

 imported into England in 

 1514 by Marshall. One of 

 the varieties was brought 

 from Holstein to Sonoma, 



California, in 1872, by Mr. J. A. Poppe, and, from 

 the five puny little fish which he placed in one 

 of his ponds in August of the same year, many 

 portions of his own State and of those adjacent 

 were supplied with scale-carp, and some were sent 

 even to the Sandwich islands. A much more ex- 

 tensive introduction of a superior breed of carp into 

 the United States was effected by the commissioner. 

 May 26, 1877, on which day Mr. Kudolph Hessel placed 

 in ponds in Druid Hill Park, Baltimore, 227 naked 

 and mirror carp and 118 common carp. These were 

 kept in Baltimore until the completion of the ponds 

 in Washington. The distribution of young carp reared 

 in Washington began in 1879, and up to the present 

 time upward of 30,000 ponds have been supplied in 

 all suitable parts of the United States. Shipments 

 have been made, also, to Colombia and Ecuador. The 

 successful domestication accomplished in Europe has 

 been repeated here. The varieties of carp known 

 among us are three : the common, or scale-carp, the 

 mirror-carp, and the leather-carp. Cart) will hybrid- 

 ize with gold-fish and with other related members of 

 the family of the Cyprinidce, forming a worthless and 



CARP (Cyprinus carpto). 



troublesome product, which can not easily be distin- 

 guished externally from true carp. Carp prefer stag- 

 nant or sluggish waters, with a loamy, muddy bot- 

 tom, and deep places abounding in vegetation. They 

 live upon vegetable food, worms, and insect larvae, 

 and will sometimes devour their own egg and the 

 bait intended for predaceous species. The} hibernate 



