/67 V \BRARV O^ ""^.'vv-VVAlf ^^^'^^ 00^ I HolUnger Corp. pH 8.5 DEPARTMENT OF COMMERCE BUREAU OF FISHERIES HUGH M. SMITH, Commissioner ARTIFICIAL PROPAGATION OF STURGEON REVIEW OF STURGEON CULTURE IN THE UNITED STATES By GLEN C. LEACH Asjisiant in Charge Division of Fish Culture U. S. Bureau of Fisheries and ARTIFICIAL PROPAGATION OF STURGEON IN RUSSIA By NICOLAS A. BORODIN Formerly Chief Specialist in Fish Culture Russian Department of Agriculture APPENDIX III TO THE REPORT OF THE U. S. COMMISSIONER OF Fisheries for 1919 Bureau of Fisheries Document No. 880 PRICE, 5 CENTS Sold only by the SuiKTintcndcut of Documents, Government Printing OfEie Washington, T). C. WASHINGTON GOVERNMENT PRINTING OFFICE 1920 Do MAR 2i 1920 ARTIFICIAL PROPAGATION OF STURGEON. Part 1. REVIEW OF STURGEON CULTURE IN THE UNITED STATES. By Glkn ('. Leach, Assistant in Charge Division of Fish Culture, U. S. Bureau of Fisheries. A number of attempts have been made in the United States at various times to propag:ate the sturo;eon by the artificial manipuhition of the I'fr^s, but in every instance they have been rendered practically null by certain unusually persistent difficulties. An account of the efforts may be of interest and value, particularly in view of the fact, as appears from the accompauyino; ])uper of Prof. N. A. Borodin, formerly connected with tlie Kussian department of agriculture, that most of these obstacles were overcome in the course of some experi- mental work performed under his direction as chief specialist in fish culture in that department. The first attempt at sturgeon propagation by a representative of the Ignited States Government was in 1888 at Delaware City, Del., In the course of an investigation of the sturgeon fishery by Dr. John A. Ryder (Bulletin, U. S. Fish Commission, 1888), but experiments along that line had been conducted by Seth Green at Xew Hamburg, N. "i ., as early as 1875, and were described by him in his book en- titled " Fish Hatching and Fish Catching," published at Rochester in 1879. The eggs for the experiment at Delaware City were obtained from fish landed for the market. A number of such fish were examined, but of the various lots of eggs secured only one suiall lot was suc- cessfully hatched. In this iustance they were taken by opening the female fish, and after fertilization had been accomplished by the application of milt secured in the customary uianner, the eggs were spread in a single layer over the cheesecloth bottouis of shallow boxes and anchored in a small sluiceway where there was a constant current of water. The same drawbacks — viz; difficulty in finding ripe eggs and milt at the same time, iuiperfect aeration of the eggs during the incuba- tion period, and the unusual tendency of the eggs to develop fungus — were again encountered in the course of a second attempt to propa- gate sturgeon at Delaware City by Dr. Bashford Dean in 1893. The work of that year disclosed the feasil)ility of using as a fertilizing medium milt secured by the removal of testes from male fish which 144957°— 20 3 4 ARTIFICIAL PROPAGATION OF STURGEON. were not sufficiently matured to void the secretion by the applica- tion of external pressure. The milt was separated from the cut testes by straining through a coarse cloth and proved just as effec- tive as that taken from live fish, even after being held for several minutes in the rubber-bulb container. In an effort to overcome past troubles, the style of hatching apparatus was changed. The eggs were spread evenly under water on shallow trays in boxes whose sides and bottoms were covered with metal gauze. The ne- cessity for quick handling soon became apparent, as the viscid nature of the eggs causes them to cling so firmly to any surface with which they come in contact that they are invariably injured in the attempt to loosen them, and it wias found that if not placed on the trays within 10 or 15 minutes after being fertilized they would form into a gluelike mass, which speedily became compact and hard. After allowing sufficient time for the eggs to become firmly attached, the trays containing them were fitted into the boxes and anchored in various places in the river bed. By the end of the second day thereafter the eggs in the boxes, which had been moored in marginal waters having a sluggish cur- rent and carrying much silt, were found to be entirely enveloped in fungus and dead. Those placed where the water current was strong and comparatively free from sediment had sustained a loss of 60 per cent by the close of the fifth day from the same cause, while those which had been installed in a strong current in salt water showed practically no fungoid growth and were hatched in good condition. In the spring of 1890 Frank N. Clark, superintendent of the North ville (Mich.) station, made preparations for the collection of sturgeon eggs at Fox Island, Mich., and under his direction 142 female and 32 male fish were examined between May 26 and June 14. Examination showed that 23 of the females had already spawned, 98 were very immature, the eggs in 6 were nearly ripe, and 5 were in spawning condition. Of the males 21 were hard, 2 almost mature, and 9 entirely so. In all, 20^00 eggs were secured and fertilized by cutting open and squeezing the milt sacs after moistening them with water. Much difficulty was experienced from adhesion, three hours of constant stirring being required to break up and separate the bunches of eggs. Ninety-five per cent of them were developed to the eyed stage, but shortly afterwards a growth of fungus began spreading in the floating boxes in which they were being incubated, and, as a result, very few of the eggs were hatched. Had it been possible to incubate them in whitefish jars it is estimated that at least 85 per cent would have been saved. In the colirse of experimental work conducted in 1901 on the Mis- sisquoi and Lamoille Rivers, tributary to Lake Champlain, efforts were made to hold green sturgeon in artificial inclosures for ripening. These' efforts proved utterly futile, as in every instance the eggs caked together in a hard mass and development was arrested. Not- , withstanding the great difficulty experienced in securing ripe eggs and milt together, 1,500,000 eggs were taken and fertilized, and their viscosity was effectively overcome by the method that is em- ployed for the separation of pike-perch eggs. They were then suc- cessfully hatched in McDonald jars, the incubation period being ARTIFICIAL PROPAGATION OF STURGEON. 5 about six days in a water temperature of 05° F. The fish from which they were secured were taken especially for the work, and their vio- lent struggles when cnuglit frequently resulted in the loss of many of their eggs. Such losses were unavoidable, as it was possible to distinguish a ripe female only when the eggs ran from it after it was taken from the water. In 1911 experimental sturgeon propagation was undertaken in Minnesota in the Lake of the Woods region. In advance of the season's run of fish an iuclosure laige enough to hold ;iO adult stur- g:eon was constructed in Rainy River, and a hatching apparatus of sufficient capacity to acconnnodate 3.000.000 eggs and fry was set up in a convenient building. During the spring IG sturgeon were captured in a pound net and transferred to the pen. Though held for several months under apparentl;^^ favorable conditions, they failed to mature, and in the following October they were released without having ])roduced any eggs. Another trial was made in the following year with the same results. From the observations made it was concluded that sturgeon do not spawn until the water has attained a temperature of 60° F. ; that the eggs do not ripen in fish held in confinement; and that unless? nearly ripe males are available when the eggs are taken no results can be expected. The spawning season at the various grounds has always been short, seldom exceeding three or four days. It is be- lieved that jars similar to those used in the propagation of white- fish and pike perch are the most suitable form of equipment for the development of sturgeon eggs. Part 2. ARTIFICIAL PROPAGATION OF STURGEON IN RUSSIA. By Nicolas A. Borodin, Formerly Chief Specialist in Fish Culture, Russian Department of Agriculture, Every fish-cnlturist knows how difficult it has been to secure any genuine success in the artificial propagation of any species of stur- geon of the genus Acipenser. There must be acknowledged almost coijiplete failure in both America and Europe as far as practical re- sults go. One drawback has been the difficulty of keeping sturgeon eggs alive and sound, owing to their liability to be attacked and killed by Saprolegnia and other kinds of fungus. Yet another and very serious matter has been the scarcity of sturgeon in the rivers and lakes; in fact, these fish in many waters have become practically exterminated, and there has been no possibility of securing ripe eggs. TMiile America and western Europe have lost most of their stur- geon supplies, Russia still remains rich in sturgeons, especially the rivers emptying into the Caspian Sea — the Volga, the Kura, and the Ural. Even in these waters, however, there has occurred positive diminution in the number of sturgeon, and it is the general belief that, in order to prevent the entire extermination of these fish, it is quite necessary to resort to artificial propagation on a large scale. Just prior to the outbreak of the war the central administration of the fisheries in Russia received a special appropriation for stur- geon propagation. Three of the commercial species were selected for attention, namely, Acipenser ruthenus, a small fish living in the Volga ; and A. guldensfadti, a Russian sturgeon and A. stellatus, or starry sturgeon, both living in the Caspian Sea and ascending the Volga, Kura, and Ural Rivers in spring. Temporary stations for the propa- gation of A. ruthe7ms were established and operated in the Volga in 1913, 1914, and 1915; one station for the propagation of A. gulden- stadfi was erected on the Ural in 1915, and another on the Kura in 1914, for handling both the starry and the Russian sturgeons. There are not at hand the exact data on the work accomplished as regards the number of eggs hatched and fry planted, but the figures for A. ruthenus run into tens of thousands and for A. steJlatus and A. gulderistadM into several hundreds of thousands. Most of the fry Avere planted several days after hatching, but a considerable number of fry of the Russian sturgeon were reared for several months, and some specimens were carried in an aquarium for five or six months, until they became too large for their quarters. There have been some interesting developments in sturgeon propa- gation in Russia in the past few years, and I will try to describe the methods employed. 6 ARTIFICIAL PROPAGATIOX OF STURGEON. 7 Two of tlie most important tlpcluctions from the investigations made during thei experimental work are that sturgeon eggs l^ecome ripe and suitable for impregnation only when the male and female fish are kept together in the same })ond or reservoir and that the si)awning act takes place probably only at night. These two observa- tions explain why it has always been very difficult to get ripe eggs from sturgeons caught during daytime or kept in ponds (yr inclosures with the male and female lish in separate compartments. In our experiments, specimens of .1. rufhe/n/.s have been held in large ponds, and their eggs have become ripe. Russian stiirgeon have been retained in a reservoir about 32 feet long, 11 feet wide, and 6 feet deep, supplied with a current of water pumped directly from the Ural River. One night these fish spawned, and two days later there were found in the mud at the bottom of the pond thousands of eggs. Some of these fish hatched into healthy fry, but, as is always the case under natural conditions, most of them had not been fer- tilized, and therefore they perished. AVith regard to artificial propagation of sturgeon, as elaborated ])y Russian fish-culturists in the latest work, the methods have been as follows: As the eggs flow from the female sturgeon they have a tendency to become united into a glutinous mass, which must at once be prevented. We received good results by stripping the eggs into a wire screen, washing them thoroughly with river water, and then putting them in a tin pan and fertilizing them with milt diluted with water. Several minutes later, before the eggs had become sticlry. we again washed them thoroughly with river water, which at this time in the Ural and Kura Rivers is very turl^id and of a yellow color, because of the enormous quantity of clay and sand in suspen- sion. By such use of muddy river water analogous to the employ- ment of swamp muck or of starch for overcoming the adhesiveness of pike-perch eggs in the United States, we counteracted the sticki- ness of the sturgeon eggs, which thereafter lose that quality and become easy to handle in any fish-hatching apparatus. We obtained quite good results in using two very different kinds of apparatus, namely, the Williamson trough and the Chase jar; but in l)oth cases we preferred to employ not running water, which is always a little nuiddy, but filtered water without circulation and with constant aeration. After three or four days of development the eggs hatched, and thousands of fry were obtained. For the first four or five days the young do not require any external food, having a sufficient quantity of nourishment in their yolk sac; but after that period we introduced into the troughs and jars living food consisting of the smallest fresh-water crustaceans (Daphnia, Bosmina, etc.) collected in small, warm watere with fine-meshed nets. The fiT soon begin to search for these crustaceans. When they become larger and accustomed to take food, we begin to feed with chopped earthworms, of which 3'oung stuigeon are veiT fond. Fed in this way sturgeon grow very rapidly, attaining during the first month a lengtli of about l\ inches and during five months 10 to 11 inches. Fry of two to three months have already begun to closely resemble the adults and are very pretty fish. O LIBRARY OF CONGRESS 002 865 882 5 L