UNITED STATES, FISH-CULTURE IN THE. 



807 



by a wet cloth ; eighteen of the trays fill a 

 crate, which is inclosed in canvas and secured 

 by frames connected by leather straps. The 

 crates are then shipped to the hatchery. 



Oysters. Artificial hatching of eggs is not 

 confined to the fishes; it has recently been 

 successfully applied to the oyster, although it 

 can not be asserted at present that this process 

 may be profitably employed in oyster-culture. 

 A great difficulty encountered by those who first 

 attempted the artificial propagation of the oys- 

 ter, was the escape and loss of the embryos be- 

 fore, they became fixed; John A. Ryder, embry- 

 ologist of the United States Fish Commission, 

 has hit upon a device for detaining the embryos 

 and compelling their fixation upon artificial 

 stools. The pond in which he operated was sup- 

 plied from the bay through a diaphragm con- 

 structed of boards perforated with auger-holes, 

 and lined on the inside with gunny-cloth, the 

 space between the boards, two inches, being 

 filled with sharp, clean sand. Through this 

 porous gate the tide ebbed and flowed, the 

 temperature and saltiness of the pond remained 

 the same as that of the bay, and the young 

 oysters found the necessary food, and grew as 

 rapidly as in the waters of the open bay. The 

 method of rearing now so largely and success- 

 fully employed is that of receiving upon arti- 

 ficial stools spat naturally produced, empty 

 oyster-shells being employed to receive the 

 seed. By such means very much has been done 

 in the New England States and elsewhere to- 

 ward increasing the market supply of oysters. 

 Another development of oyster-culture is the 

 planting of oysters upon suitable bottoms and 

 allowing them to remain there to grow and 

 fatten. 



Sponges and Lobsters. Sponges have been arti- 

 ficially propagated from cuttings. Illustrations 

 of sponge-culture were shown at the Interna- 

 tional Fisheries Exhibition, by McKesson and 

 Robbins, of Florida. It is claimed that this 

 may become a successful industry. The arti- 

 ficial culture of lobsters has received much at- 

 tention in some of the European countries. At- 

 tempts have been made by the United States 

 Fish Commission to transport adult lobsters to 

 the Californian coast, but without successful 

 results from the introduction. 



Results of the Commission's Work. Most of the 

 States have fish commissioners, who undertake 

 to supply the streams of their own States. The 

 General Government occupies itself with such 

 bodies of water as the great lakes, with rivers 

 which no single State or combination of States 

 could be expected to take under its charge, 

 and with marine species. It undertakes, also, 

 the acclimatization of species which must be 

 brought long distances and at great expense, as 

 well as transportation across the continent, and 

 even to remote countries. Some of the results 

 are so well known that it seems hardly neces- 

 sary to mention them. We might refer to the 

 successful introduction of the shad in the Mis- 

 sissippi Valley and upon the Pacific slope ; to 



the improvement of the shad-fisheries in nearly 

 every important river which has recently been 

 stocked; to the great impression made upon 

 the coregonus fisheries of the great lakes; to 

 the deposit in 30,000 ponds of the German 

 carp; to the annual increase of nearly 5,000,000 

 pounds of salmon in the Sacramento river, due 

 to the artificial breeding in the McCloud ; to the 

 successful introduction of the California salmon 

 into Europe, where it thrives in ponds ; and to 

 the general improvements in fish-hatching ap- 

 paratus. 



Practical Information. The limitations of fish- 

 culture are purely physical. Cold or obstruc- 

 tions or impurity of the water, may neutralize 

 the efforts of the fish-culturist. just as frost, or 

 flood, or plague, may render unavailing the 

 labors of the agriculturist ; but the practicabil- 

 ity of the art remains the same. Because of 

 the general interest in several of our native 

 species, I append brief descriptions of the meth- 

 ods employed in their propagation. The notes 

 relate to some of the salmonoids, the shad, and 

 the carp : 



Trout and Salmon, One of the first requisites for 

 hatching eggs of the Salmonidcn is a steady supply of 

 pure springs-water, having a uniform and low tem- 

 perature. If the water contain sediment, this must 

 be kept out of the hatching-apparatus by a series of 

 filters. Perhaps the best temperature of water for 

 hatching purposes is about 45 Fahr. ; it would not 

 be well to have it much higher. In water of 45 

 trout-eggs will hatch in about seventy-five days, and 

 the yolk-sac will remain nearly fifty days longer. For 

 the proper accommodation of the apparatus and the 

 embryo fish, a hatching-house is necessary. Neither 

 rain-drops nor the sun's rays must fall upon the eggs. 

 Modern apparatus made of glass, and closely sealed, 

 except where the water enters and escapes, will pre- 

 vent numerous accidents. 



Connected with the hatchery must be a series of 

 ponds, which should be at different levels and united 

 by long, narrow race-ways. The rearing-pond.s arc to 

 be supplied with brook or river water of a tempera- 

 ture never exceeding 65 Fahr. The fishes of each 

 pond must be prevented by screens from leaving their 

 mclosure. The depth of ponds is made to vary with 

 the size of the fishj and from the head, where it is 

 usually about six inches, to the foot, which, in the 

 largest pond may measure six feet. It is customary 

 to construct ponds narrow and long, with a view of 

 sweeping them readily with a seine. It is desirable 

 to arrange the ponds BO that they can be entirely emp- 

 tied when necess'ary. Fish kept in confinement must 

 be fed. Feeding should begin a week or two before 

 the yolk is entirely absorbed. One successful fish- 

 culturist uses a mixture of the yolks of nine eggs with 

 one pound of beef, which is pressed through a fine 

 sieve. Livingston Stone believes that young living 

 perch and suckers, which can readily be obtained in 

 abundance, would probably be the best food for very 

 young trout ; but as artificial food he recommends 

 liver and curd from sour milk in about equal propor- 

 tions, or with two parts of liver to one of curds. Raw 

 liver alone is extensively used : it must be chopped 

 quite fine and pressed "through a fine sieve. Seth 

 Green reduces it to the consistency of pulp, and, after 

 diluting it with water to about the thickness of cream, 

 gives a teacupful of the mixture to 100,000 fish just 

 beginning to feed. The larvae of gnats, as well as of 

 Daphnia, Cyclops, etc., may be skimmed off stagnant 

 waters with a fine muslin net, and fed to the young 

 fish. Whatever is given to the frv, care must be taken 

 that it does not choke them, and no refuse must be 

 allowed to remain in the water to putrefy. 



