SH fa as 1o7 U.S, COMMISSION OF FISH AND FISHERIES, S6U5 eae Ie GEORGE M. BOWERS, Commissioner. “ARTIFICIAL PROPAGATION | OF THE Extracted from the Revised Edition of the Fish Manual. Pages 121-145 and 165-179 | Plates 40-46 and 51-52, \ WASHINGTON: GOVERNMENT PRINTING OFFICE. ; 1908. Class_ 5S H\ 6% Bok. 10 SUB ca i! ‘a wer 4 ai tat ee , U.S: COMMISSION OF [FSI ANID FSIIEIRINES: GEORGE M. BOWERS, Commissioner. ARTIFICIAL PROPAGATION OF THE SHAD AND PIKE PERCH. Extracted from the Revised Edition of the Fish Manual. Pages 121-145 and 165-179, Plates 40-46 and 51-52, WASHINGTON: GOVERNMENT PRINTING OFFICE. 1903. PLATE 40. (To face page 121.) Fish Manual. "PYYS' WOUNWOD “WINISSIGIdVS YSOTY THE SHAD. DESCRIPTION OF THE SHAD. The shad (Alosa sapidissima) is the largest, best-known, and most valuable member of the herring family in the United States. The body is deep and compressed, the depth varying with the sex and spawning condition, but averaging about one-third the body length. The head, contained about 44 times in the body length, is quite deep; the cheek is deeper than long. The jaws are about equal, the lower jaw fitting into a deep notch on the tip of the upper. Teeth are present in the young, but are not found on the jaws in the adult. The eye is contained 52 to 6 times in the length of head. The gillrakers are long, slender, and numerous, there being from 93 to 120 on the first arch. The fins are small and weak, the dorsal containing 15 rays and the anal 21. The lower edge of the body is strongly serrated, the plate-like scales numbering 21 before the ventral fin and 16 behind it. The scales in -_ the lateral line number 60. The bodyis dark-bluish or greenish above, silvery on the sides, and white beneath. There is a dark spot behind the gill-opening and sometimes a row of smaller spots along the side. The vertical fins often have black or dusky edges. The peritoneum is white. Supposed structural and color peculiarities in shad from different regions or basins have not been verified. From the other clupeoids with which the shad is frequently asso- ciated in the rivers, it may be readily distinguished. In allof them the cheek islonger thandeep. The hickory shad or hickory jack (Pomolobus mediocris) has a projecting lower jaw and a very straight profile. The river herrings or alewives are much smaller than the shad, have fewer and shorter gillrakers, and a larger eye (34 in head). In the branch herring (P. pseudoharengus) the peritoneum is pale, while in the glut herring (P. estivalis) it is black. The female shad is larger than the male, the average difference in weight being more than a pound. The mature males taken in the fisheries of the Atlantic coast weigh from 14 to 6 pounds, the average being about 3 pounds; the females usually weigh from 3 to 6 pounds, the average being 4% pounds. The general average for both sexes is between 3? and 4 pounds. In the early history of the fisheries, shad weighing 11, 12, and even 14 pounds were reported, but 9-pound shad are very rare on the Atlantic coast, and 10 pounds seems to be the maximum. Some seasons an unusual number of large shad (7 to 9 pounds) appear in certain streams. On the Pacific coast shad average a pound or more heavier than on the Atlantic, occasionally attaining a weight of 14 pounds; many have been reported weighing 9 to 12 pounds. ; 121 122 REPORT OF COMMISSIONER OF FISH AND FISHERIES. DISTRIBUTION AND ABUNDANCE. The shad is distributed along the entire east coast of the Uniteo States, and northward and eastward to the Gulf of St. Lawrence. It has gradually spread from the Sacramento River, California, where it was introduced by the California Fish Commission, and is now taken from southern California (Los Angeles County) to southeast Alaska. In the early history of the country its abundance excited unbounded astonishment. Nearly every river on the Atlantic coast was invaded in the spring by immense schools, which, in their upward course, furnished anample supply of good food. Notwithstanding greatly increased fish- ing operations and the curtailment of the spawning-grounds, the supply in recent years has not only been generally maintained, but owing to fish-cultural efforts has been largely augmented in certain streams, notably in the Kennebec, Hudson, Delaware, Susquehanna, Choptank, Potomac, Nanticoke, Rappahannock, York, James, Chowan, Roanoke, Neuse, and St. Johns rivers, and in Chesapeake Bay, Albemarle Sound, Croatan Sound, and Pamlico Sound, and the Sacramento and Columbia rivers. SHAD IN THE OCEAN. The shad passes most of its existence. at sea, and little is known of its habits and movements when out of the rivers. The ocean areas to which it resorts are unknown, and what its salt-water food consists of has not been determined. In the Gulf of Maine it is known to associate in large numbers with mackerel and herring during the months of June, September, and October, being most numerous in June. It has been taken at North Truro, Massachusetts, in the fall, when the ocean temperature was from 45° to 49°. In the month of November, one year after another, it has been found on the west side of Sakonnet River, Rhode Island. In May and June it has been captured with mackerel a few miles northeast of Cape Cod Light. Some instances of capture indicate that under certain conditions the adults may remain in the fresh-water rivers a whole year. In November, 1890, 600 were taken in the Chesapeake Bay. It has been found in the Potomac in cousiderable abundance in August and September, and even during the last week in December. Its movements are largely controlled by the water temperature. It is believed that it seeks to occupy an area having a temperature of 60° or 70°, and that its migrations are deter- mined by the shifting of this area. SHAD IN THE RIVERS. The annual migration of the shad from the ocean to the rivers is for the sole purpose of reproduction. It ascends to suitable spawning- grounds, which are invariably in fresh water, occupying several weeks in depositing and fertilizing its eggs in any given stream. Its migrations from the sea are in quite a regular succession of time with relation to latitude. It first appears in the St. Johns River, MANUAL OF FISH-CULTURE. 123 - BPlorida, about November 15, the season of greatest abundance being February and March. In the Savannah River, Georgia, and the Edisto, South Carolina, the run begins early in January and ends the last of March. In the North Carolina rivers these stages of the migration are a little later. In the Potomac River advance individuals appear late in February, but the fish is most numerous in April. In the Delaware River the maximum run is about the Ist of May.. It reaches the Hud- son River the last of March, and is found in the Connecticut toward the end of April, is most abundant the last of May, and leaves the stream late in July. In the Kennebec and Androscoggin rivers, Maine, it is first taken in April and has left by the middle of July. In the St. John River, New Brunswick, it appears about the middle of May, and in the Miramichi River, New Brunswick, late in May. The main body of shad ascends the rivers when the temperature of the water is from 56° to 66°, the numbers diminishing when the tem- perature is over 66°. Successive schools enter the Potomac from February to July, the males preceding the females. Of 61,000 shad comprising the first of the run received at Washington, D. C., from March 19 to 24, 1897, 90 per cent were males. Toward the close of the season males are extremely scarce. The movement of the shad up the rivers is not constant, but in waves, causing a rise and fall in the catch. In some of the rivers the fishermen claim that a fairly well-defined run occurs late in the season, consisting of a somewhat different tish, known as “‘ May shad.” The erection of impassable dams along the rivers and streams was probably the first thing to curtail the natural spawning-grounds of these fish and to seriously check their natural increase. As shad enter the rivers only for the purpose of spawning, the fisheries are necessarily prosecuted during the spawning season, and often upon the favorite spawning-grounds. The increase of population necessitates a larger supply of fish and requires the use of more apparatus, and the number of shad that reach fresh water is therefore greatly curtailed by assiduous fishing with all kinds of contrivances in the estuaries and in the mouths and lower parts of rivers. Under these conditions of a restricted spawning area and increased netting shad would soon be exterminated without artificial propagation; or the fish- ery, at least, would greatly diminish and become unprofitable. Such a crisis was fast approaching in 1879, when the Fish Commission entered upon systematic work in shad propagation. - From their birth until their return to the rivers shad are preyed upon incessantly by other fish, so that the larger portion of the young do not survive their few months’ sojourn in fresh water, and of those which leave the rivers each season probably not one in one hundred reaches maturity to deposit its eggs and contribute to the perpetuation of its species. In the rivers striped bass, white perch, black bass, and other predaceous fishes devour the young, and when they reach salt water, sharks, horse-mackerel, kingfish, etc., undoubtedly destroy many 124 REPORT OF COMMISSIONER OF FISH AND FISHERIES. adults. It has been observed by North Carolina porpoise fishermen that as the shad swim close along the shore the porpoises follow and, feed on them till they pass into fresh water. In the rivers the adult shad is comparatively free from enemies. To what extent the pollution of tLe waters has rerineadl the numbers ~ of shad is not known, but acids, sawdust, garbage, oils, gas tar, and refuse from dye-works all tend to make the water of rivers unsuitable for them. FOOD. After entering the rivers, the shad takes but. little, if any, food previous to spawning, but after casting its eggs it. bites at flies or any small shining object, and has been known to take the artificial fly. The mouth of the adult is practically toothless, and its throat contains no functionally active teeth. The water which passes through the branchial filter—the gillrakers—is deprived of the small animals which are too large to pass through its meshes. It is a common remark with fishermen and others that food is rarely found in the stomach of the adult shad in fresh water, but examinations have shown that the shad does, in some instances, eat small crustacea, insects, etc. The only substance commonly found in its stomach in fresh water has the appearance of black mud. It is held by some that the shad swims with its mouth open and may unintentionally swallow the small organ- isms found in its stomach under such circumstances, but as far as observation of fish in aquaria and experiences of net fishermen go, the shad does not swim with its mouth open. NATURAL SPAWNING. Shad are liable to be ripe anywhere above brackish water, and under favorable temperature conditions spawn wherever they happen to be, but in some river basins they exhibit a well-defined choice of spawning- places, preferring localities below the mouths of creeks, where the warmer water of creeks mingles with the colder channel water. The shad lays its eggs during the highest daily average temperature, a con- dition realized about sunset, when the warmer shoal water commingles with the colder channel water, establishing a balance. The principal spawning occurs from 5 p.m. to 10 p.m. Observations on the Potomac Ktiver show that of the eggs from shad caught in a seine only 11 per cent were taken between midnight and noon, the percentage in the morning being 14 one year and 8 another. The eggs in the ovaries remain in a compact mass until they ripen, at first occupying but a small space, but gradually increasing until they distend the whole abdomen, the average weight of the ovaries being about 13 ounces. Close examination at the approach of the spawning time will disclose large maturing eggs of rather uniform size and others smaller and of variable size. Whether the latter are the forming eggs for the next year, for two or three succeding years, or for the lifetime of the fish has not been determined, nor is it known whether shad spawn every year. The small and shrunken ovaries of a spent fish are still PLATE 41. Fish Manual. (To face page 124.) WES SES a Ne “I ne eS : 4 pk ‘ Qa > La ee a, « — ae ie ERNE fal j-6\'X 90 esep == SEITEN. LAE EIOX SENET NA. Soy VaR ATIVE YT 44 [NASEAD EU Pe as IGIOITEEN Lo as “vA & a Fs CUT E Uty ENY a Swe SPA EeArereits aw : Vx) Zee Za TOO mH ¥ tor BAA SON sy zuata fl 7 — So8 PeTETRITE lh li ] i i Titi ya tyr a v E2 2} elma —- Oni on wn RS oe pw as A com LAAT} i Gets A, Freshly extruded egg enlarged, showing its envelope much wrinkled and its surface covered with smallround vesicles. B. Shad egg, showing vitellus and distended egg-membrane, natural size. C. Shows the gradual accumulation of germinal matter at one pole of egg, the polar prominence ex- ternally, and presence of plasmic processes extending down through the vitellus. D. Embryo shad in its natural position in its spacious enveloping membrane. From a photograph. H. Diagrammatic representation of an embryo to show course of segmental ducts sd and extension outward of pectoral plates pp, which are intimately concerned in the development of pectoral fins. F. Side view of a young shad 13 days old, viewed as a transparent object. ab, rudimentary air- bladder; ZL, liver; Gb, gall-bladder. G. An embryo in its envelope, on the third day of development, nearly ready to hatch. Fish Manual. (To face page 124.) PLATE 42. H and a Ewe views of an egg after the blastoderm has spread considerably and the embryonic area e is well defined. K. View of unhatched embryo, which developed in a temperature of 45° F., producing distortions of tail and notochord. L. An egg-envelope with its contained embryo, forty-four hours after impregnation, viewed as a trans- parent object. M. An egg-envelope with its contained embryo at the beginning of the third day of development. From a photograph. 5 NV. Anterior portion of a young fish on fourth day. To show relations of liver L to yolk Y, over which the portal vessel pv passes forward to empty into the venous sinus, in common with the anterior and posterior jugulars 7’ and j, ba bulbus aorte, ve ventricle. O. View of fore part of a young fish 17 days old, from ventral side. Fish Manual. (To face page 124.) PLATE 48. P. Young fish immediately after hatching, viewed as an opaque object and somewhat obliquely from one side, to display the relations of branchial and hyomandibular arches, and position of pectoral fin. @. Young fish third day after hatching, viewed asa transparent onject to show extension of segmental duct forward; chorda ch, R&. Young fish5 days after hatching, very much enlarged, and viewed as an opaque object. Only a slight rem- dant of the yolk-sac Y remains. S. Young fish 17 days after hatching, viewed partly as an opaque and partly as a transparent object; py pylorus and rudimentary air-bladder above it; J intestine, filled with the remains of ingested food. The opercula are already so far developed as partly to conceal the gills. eet thee MANUAL OF FISH-CULTURE. 125 found full of these eggs of different sizes. Shortly before spawning, transparent eggs of large size, contrasting strongly with the opaque golden hue of less mature ones, will be found scattered through the still compact ovarian mass, and, becoming more and more numerous, the! ovaries disintegrate, the eggs fall apart, and extrusion begins, a liquid. stream of eggs and mucus flowing from the oviduct on the slightest pressure of the abdomen. Freshly deposited shad eggs are of a pale amber or pink color, and . are transparent. They are about +; inch in diameter and somewhat flattened and irregularly rounded in form. The egg membrane is much wrinkled and lies in close contact with the contained vitellus. Inme- diately after fertilization the egg becomes spherical through the absorp- tion of water and apparently gains very much in bulk, measuring about, + of an inch in diameter; but this gain is only the distended egg mem- brane, the vitellus or true germinal and nutritive portion not having increased. The vitellus is heavier than water, and a large space filled with fluid now exists between it and the membrane, the vitellus rolling about and changing its position as the position of the egg membrane is altered. Noadhesive material is found on the outside of the membrane, though when first extruded the eggs are covered with a somewhat sticky ovarian mucus. In a state of nature the shad deposits its eggs loosely in the rivers without building a nest, the two sexes running along together from the channel towards the shore, and the eggs and milt being ejected simultaneously. On quiet evenings, at the height of the season, spawning Shad may be heard surging and plunging along the shores. By fishermen this is termed “ washing.” Shad are very prolific, but much less so than many other food-fishes. The quantities of eggs taken by spawn-takers do not represent the actual fecundity, for many are cast in advance of stripping. The | average number is not more than 30,000. Single fish have been known | to yield 60,000, 80,000, 100,000, and 115,000 eggs; and on the Delaware River, in 1885, one yielded 156,000. Many eggs fail to be fertilized, and but a comparatively small percentage of those impregnated are— hatched. After being extruded, the eggs sink to the bottom, where > they remain until hatched, subject to the attacks of fish and other water animals. Eels are very destructive to shad spawn and often | attack shad caught in gill nets, devouring the undeposited eggs and sometimes mutilating half the catch of a gill-net fisherman. The development of fungus is one of the greatest dangers to shad , eges ina natural state, and another potent agency for their destruction | is the mud brought down by heavy rains, burying and suffocating the eggs. After spawning, shad are denominated ‘‘down-runners,” ‘‘racers,” | and “spent fish.” They are then very lean and hardly fit for food, but they begin to feed and have become fatter by the time they reach salt | water in the summer or fall. 126 REPORT OF COMMISSIONER OF FISH AND FISHERIES. YOUNG SHAD. In the Middle States the young fish remain in the rivers, feeding and growing, until the cool weather of fall comes on. They then ‘begin to drop downstream, and by the last of November have passed out into the ocean or bays, and are lost sight of until they come back three or four years after, full. grown and ready to spawn. They leave the Potomac River when the water falls to about 40°. By that time they are about 3 inches long. For the last two or three years they have been observed in great abundance about Bryan Point, feeding and jumping out of the water about sunset. They keep within the open streak of water between the shores and the water-grass which covers the flats, in water 2 to 5 feet deep. After mild winters young shad have been found in the Potomac River in April, 30 miles above brackish water and 160 miles from the ocean, associated with young alewives and sturgeon. Some immature shad, apparently 2 years old, are caught each year in seines operated in the fresh water of the Potomac River, ‘and undersized shad are frequently caught in the New England rivers, _where the tidal waters are of little length. COMMERCIAL VALUE. The shad is one of the most palatable and popular of fishes. Its flesh is rich, but not oily, and the roe is considered a delicacy. It is the most valuable river fish of the Atlantic coast, and, next to the ' Pacifie salmon, the most important species inhabiting the fresh waters of North America. In every Atlantic State from New Jersey to Florida, inclusive, it is the most valuable fish, and in New York it is second only to the bluefish. Among all the economic fishes of the United States only the salmon and cod exceed it in value, and, considering all branches ‘of the fishing industry, only the whale fishery and the oyster fishery, besides the foregoing, are financially more important than the shad. In 1896 the shad catch of the Atlantic seaboard numbered 13,145,395 fish, weighing 50,847,967 pounds, and worth to the fishermen $1,656,580. The value of the shad catch of the Pacific States in 1895 was $5,600, a “sum representing 366,000 pounds. EARLY ATTEMPTS AT SHAD-CULTURE. The systematic development and extension of shad-culture were ‘undertaken with the definite purpose of testing the value of artificial propagation in maintaining an important fishery which was being’ ‘rapidly depleted. As early as 1848 shad eggs were artificially taken and fertilized, and in 1867 more extensive experiments were made on the Connecticut River, and later on the Potomac, with encouraging results. The attention of many States was thus attracted to the work, and in 1872 it was taken up by the general government. Prior to the experiments on the Connecticut, certain species of the salmon family had been principally dealt with in fish-culture, and different. methods _from those in use were necessary for shad-hatching, owing to the less ‘specific gravity of shad ova and the much shorter period of time required for the development of the fish from the egg. MANUAL OF FISH-CULTURE. L270 The “Seth Green box,” a modification of the floating-box used for hatching trout and salmon eggs, was first tried with great success, but floating-boxes were subject to various accidents when used in tidal waters, and in rapid succession devices of various kinds were brought forward to supplant them. The most important were hatching- -cones and the plunger-buckets, which, though imperfect, rendered larger operations possible. At this period the apparatus was arranged on_ flat-bottomed barges and towed from point to point along the coast from Albemarle Sound to the Susquehanna River, a slow and expensive method. The Chase whitefish jar worked with considerable efficiency, but required modifications, and finally the “universal” hatching jar now in use was adopted in 1882. During the years of experimental work from 1872 to 1880, 97,471,700 shad fry were planted, beginning with 859,000 in 1872, while in 1880, 28,626,000 were distributed. Prior to 1880 deposits of a few hundred thousand each were made in as many different streams as possible, but the increased production of young fish made it possible to ship and plant the fry by the carload, and by 1884 shad-culture was established on a large scale, barge operations were abandoned, and the work conducted on shore. The basins of the Chesapeake Bay and Delaware River had meanwhile been selected by the United States Commission as the natural seat of operations, though the State commissions from’ Massachusetts to South Carolina were actively engaged on their own account. At present the States, except Connecticut, New York, Penn- sylvania. and Maryland, have practically syanionel shad- Sparta, leaving the work to the general government. EGG-GROUNDS. Every river on the Atlantic coast from Massachusetts southward has been examined by the agents of some State commission or the United States, or by both, in order to determine the natural spawning-grounds of the shad. On nearly every stream hatcheries have been operated at one time or another, but usually eggs were not obtained in sufficient numbers to justify continued operations, except in the Chesapeake and Delaware basins. However, it is not unlikely that after further investi- gation it will be found practicable to maintain hatcheries on rivers which have long since been abandoned. It is certain that work on the Albemarle Sound can be successfully conducted, and though operations on the Hudson River have not been on a large scale, better results may be there obtained i in the future. In certain river stretches, apparently favorable, no ripe fish are found ; for example, in the Roanoke River for 15 miles above its mouth, where 10,000 to 15,000 shad are taken annually, mature eggs can not be found, though the fish spawn just below there, as they do many miles above at Weldon. In the Sutton Beach seine, the one in North Carolina waters _ which has afforded the most spawn, only about one spawning shad to each 100 is caught, and the annual catch of this seine is 30,000 to 75,000 per annum. In view of such facts, it is not remarkable that difficulty 128 REPORT OF COMMISSIONER OF FISH AND FISHERIES. has been experienced and time consumed in deciding on permanent loca- tions for hatcheries. The spawning period varies widely in different seasons ; in some years shad are numerous and in spawning condition two or three weeks after the time when they have ordinarily disappeared. They deposit eggs at some point along the coast for six continuous months. The following streams have been occtipied by hatcheries, as some of them are now, and it will be observed that the approximate spawning periods, beginning early in the South, become gradually later toward the North. Waters. Place. — Period. | TDGMEIO INVEsc choca oceascacsscade Jacksonboro, 8. C..--.-------- | Mar. 5-26. Albemarle Sound......---------- Avoca: NY Cree: a. eceeeiauiene | Apr. 1-30. | Potomac River .----------------- Below Washington, D. C.----- Apr. 15 to June 10. Susquehanna River. --.---------- Below Havre de Grace, Md .--. Apr.17 to June 15. Delaware River. --.------:-------- | Gloucester, N. J.------------- May 10 to June 20. Hudson River -.------------------ Below Albany, N.Y..-------- | May 15 to June 30. Housatonic River..---.------------ Birmingham, Conn......------ | Do. Connecticut River. -------------- | Holyoke, Mass....-..--------- June 15 to July 5. Merrimac River ----------------- North Andover, Mass..--.---- | June 1 to July 15. The United States Fish Commission operates stations at Bryan Point, 12 miles below Washington on the Potomac, and at Battery Island at the mouth of the Susquehanna, while the steamer Fish Hawk, fitted up as a floating hatchery, is engaged during the shad season on the Delaware River. These two stations and the vessel can receive respectively 16,000,000, 40,000,000, and 12,000,000 eggs. On more than one oceasion each has been taxed to its utmost capacity, but as the average hatching period is 8 days, and four of the special cars of the Commission are hatcheries in themselves and capable of taking 2,000,000 to 4,000,000 eggs aboard at a time, the hatcheries can be quickly relieved in case of emergency. In 1897, 205,000,000 eggs were taken, from which 134,045,000 try were hatched. In 1898, the total of shad fry hatched was 156,150,000, and in 1899 it was 210,493,000. In 1900, a permanent hatchery located on an arm of Albemarle Sound, near Edenton, North Carolina, was operated for the first time. This sta- tion is adjacent to one of the most important shad fishing- grounds in the country, and is intended to replenish the waters of Albemarle, Croatan, Roanoke, and Pamlico sounds, and their tributaries—the Pasquotank, Chowan, Roanoke, Pamlico, Neuse, and various minor rivers. This region annually yields upward of 8,500,000 pounds of shad, valued at about $350,000, and contributes the principal part of the shad found in the northern and eastern markets in winter and early spring. Potomac River.—The Potomac River, immediately adjacent to Fort Washington (12 miles below Washington, D. C.), is probably more pro- ductive of ripe shad than any other area of the same size. This was ‘VHS ONIHOLVH YOS GaddINOZ 'MMVH HSI4 YSWVSLS SHL 4O YORG NIVIN Fish Manual. (To face page 128.) GIES RI NE SRS PLATE 44. se binant —, ee —recs MANUAL OF FISH-CULTURE. 129 discovered as early as 1880, and a station was soon developed there with steam pumps, tanks, and hatching vessels. The seine operated at this point between 1887 and 1891 furnished 23 per cent of all eggs from the river. The following table, taken from the records of the station, shows the value of the spawning-grounds: ( Years. ae Years oar pails yl Eda Na mu pee TBO Renee cers ty eae Hoe ZoMooowellleiiaote ut) Scie euet | 32, 980, 000 ACR ences | 43,200,000. | TER Ge a | 13, 446, 000 FUSES on a } 2 B00}000N8| a 1e03e-t ee tees || (97493, 000 1983 seine Serer Maro oa a law OH Oe (OOO) Gill WEDS s Shebeesegoeuccecos | 32, 393, 000 Gey een, See ag a ©; Wen), 000° II) WH canes ss eeasacne 66, 065, 000 BSB N we teeta Ae dee 2 BG, OOD. || REGsso sean sandesacses 64, 788, 000 USSG eetee retecleeeis ert nt NG GPL ONO all: sWePtecesouvasoscessecse | 39, 707, 000 IIe sn anne [a5 904 35,,0008 MenlGO Resta cto ar | 68,724, 000 SBS eee nett 1: Si 177 O00 | eal SOO Mee nessun nie eee ne | 49, 283, 000 URQuE Ne eee etncr ns s | BeLORS: OD lll TEs. 2 sbebcgeesedaeee | 67, 904, 000 Wiasl8 90) see esters endo. 35 4202. 000) | | i In 1889 immense collections of eggs were made on certain days— 8,368,000 on May 6 and 6,311,000 on May 7, and during seven days there was an average of over 5,000,000 per day. This was before and just after a freshet. To increase the supply of eggs, seine fishing has been attempted by the Commission on both the Susquehanna and Potomac, but the efforts were only partially successful and were finally abandoned. The exten- sion of egg-taking by seines can not be relied upon, especially as this method of fishing has been declining for many years, owing to its greater expense, and a corresponding growth has taken place in the gill-net fishery. It is often difficult to obtain the ripe eggs when the shad are taken in a seine on account of the great numbers of alewives taken at the same time. The following comparative table shows the shad-egg production from a Potomac River seine, together with the proportion of males, females, and spawning fish, and the number of eggs per fish: Total Average car| Lotal Total | Per cent | Percent! number | : Year number of | ripe shad of of of eggs Pen cent = BT fish. | caught. | males. | females.| per fish | a i spawned. I eisencoceces 20, 956, 000 652 10, 348 71.4 28.6 32, 100 6.3 IE cososeese 22, 657, 000 688 11, 212 69. 2 30.8 32, 900 | 6.1 1889.......--.| 17, 738, 000 612 6, 217 52.3 47.7 28, 980 | 9.8 S90 Bee ae 10, 262, 000 468 4, 606 54.3 45.7 21, 900 | 10.1 SOT eee 5, 276, 000 228 3, 188 | 57.1 42.9 23,140 | 7.2 | | | F. M.—49 130 REPORT OF COMMISSIONER OF FISH AND FISHERIES. Had all other fisheries furnished an equal percentage of eggs, the annual Potomac collections would have reached about 300,000,000. But while the Fort Washington seine, with a catch of 10,000 shad, gave 20,000,000 eggs, and another, capturing 18,000, gave 17,000,000, a third catching 60,000 shad, gave only 1,000,000. Eggs taken by gill fishermen are usually superior to those from seines, and the gillers attach enough value to the market for eggs to save almost all within reach. At the commencement of the season many of them secure spawning-pans, which they keep in their boats, taking and fertilizing the eggs themselves, and when accidentally overlooked by the regular spawn-takers they sometimes row several miles to bring in pans of eggs. In 1896 a giller who laid out his net with the special object of securing spawning shad, caught 3,300 fish and sold over 6,000,000 eggs to the Commission. About 1,100 of his fish were roe shad; of the total, about 6 per cent were ripe; of the 1,100 roe, about 20 per cent were ripe. The average catch of shad by the gillers who supply eggs is 1,600 to 1,800 per season; but they do not all operate specially for the capture of spawning fish, though this work is profitable and gillers are fast turning attention to it. The Fort Washington gilling boats furnish on an average about 1,000,000 eggs each a season, those at White House 400,000, Sandy Bar 350,000, Greenway 300,000, and Craney Island 150,000, the average peine about 500,000 per boat Gisnmeenan River.—The shoal water in the neighborhood of Battery Station is an extensive and valuable spawning-ground. The station is conveniently situated on an island and the possibilities in egg- collecting appear to be almost unlimited. Hundreds of gill fishermen are engaged and large seines are operated within easy distance. In 1886 the station was overrun with eggs; 170 universal hatching-jars and 58 cones would not contain them, large numbers being held in cylinders, buckets, and pans. In 1888 over 105,000,000 were taken, and in 1889 7,600,000 were obtained in one night. Both egg-collecting and hatching are carried on, and the establishment is complete in itself. There is no transfer of the eggs except for occasional car shipments, and the fry are carried to Havre de Grace in 10-gallon cans for railroad transfer to the piaces of deposit. Delaware River.—The steamer Fish Hawk has been employed in shad- hatching on this river nearly every season since 1887, the egg-collecting and other labor being performed by the crew. An interesting feature of the work is the large yield of eggs per fish. Eggs from this river have been saved regularly since 1887 from seines, but the available product among the gill fishermen has never been fully ascertained. The eggs collected by the Fish Hawk pumbered 51,983,000 in 1899. The methods pursued at the different shad hatcheries are very similar. The following description applies particularly to the work on the Poto- mac River at Bryan Point. PLATE 45. (To face page 130.} Fish Manual. BATTERY STATION HATCHERY, HAVRE DE GRACE, MARYLAND. MANUAL OF FISH-CULTURE. 131 EGG-COLLECTING. Collecting eggs is the work of experienced watermen, who must be prepared to endure all kinds of weather in open boats. The boats are towed out to the fishing-grounds by steam-launches, where the spawn- takers visit the nets of the market fishermen, obtaining from them the spawning fish. After eggs have been obtained a ticket is dropped into each panful, with the date and the name of the fisherman, for entry on the books of the station. The price for eggs is always above the market price of the shad, and payment is made at the end of the season on the basis of 28,000 to the liquid quart, the price being $10 to $20 per 1,000,000. On the Potomac 40 to 50 spawn-takers are employed at the station, besides 12 or 15 men who are engaged as hatching attendants, machinists, firemen, and cooks. . The spawn-taker uses a 16-foot flat-bottomed bateau and is provided with a lantern, six small and four large spawn pans, and a dipper of suitable size. The pans are made of tin and are of two sizes, 11-inch and 18-inch diameters, the latter with handles. The smaller are for receiving eggs on delivery from the fish, and the larger for carrying them. The pans are thoroughly washed each night after use and not allowed to become rusty orindented. The dippers are round-bottomed, hold nearly a quart, and have handles with open ends, with 5 inches of the free end wrapped with seine twine. To obtain eggs from a seine, double the above number of spawn vessels may be required. Spawn-taking tubs of indurated wood fiber have been introduced in Potomac River operations and found superior to tin, being without hoops or joints, non-corrosive, and non-conductors of heat. They have wood covers which fit inside the rims, and the tops fit tightly by means of a soft rubber joint: 4 inches of the central part of ‘the cover is cut away to admit air. As the shad manipulated are sold and consumed in a fresh state, fishermen waste no time in transferring them to market boats, which are in waiting, and rapidity of execution is therefore required on the part of the spawn-taker, who must be alert and exact in his methods. In gill-net fishing there is usually ample time to assort the fish, which are taken into the boat one at a time, except when sudden squalls or exceptional captures force the premature hauling in of the net with the fish wound up in the meshes. Unskilled spawn-takers are liable to the mistake of stripping eggs without having the neces- sary mjlt to impregnate them, for several spawners may be taken over a period of ten or twenty 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. Sometimes the number of ripe fish will be sufficient to occupy all the attention that can be devoted to them; at other times the run of fish 132 REPORT OF COMMISSIONER OF FISH AND FISHERIES. is greatly reduced by local conditions. HEven when other conditions are Satisfactory, if neither high nor low water occurs about sunset but few ripe fish are caught. The large seines land toward the last of the ebb tide, and gill net fishermen can do nothing except on the change of the tide—on slack water. The fish spawn at a certain time of day, and when taken at other hours are not in spawning condition. Thun- derstorms sometimes occur for days in succession about sunset, the very hour when most disastrous. A scarcity of male fish toward the end of the season often cuts short — operations when eggs are plentiful. Unsuccessful attempts have been made to capture the males at such times by using gill nets with meshes smaller than those in the nets of market fishermen. Attempts have been made to pen the adults, but without success, as the fish become diseased and their eggs spoil within them. In gill nets the adult is entangled in the mesh and can not escape by struggling, and it therefore remains comparatively quiet. The quality of shad eggs is generally impaired where the fish are held for an hour or more in trap nets or seines. The eggs from fish taken in large seines are usually of bad quality, but those from short seines, which are landed quickly after the fish have been surrounded, are usually good; and those from trap nets, in which the fish have been held for some hours, are valueless. Eggs are rarely susceptible to fer- tilization longer than 20 minutes after the fish are taken from the water, though there are exceptions to this rule. On May 23, 1895, Potomac shad were stripped which had been out of the water about 14 hours; they were kept separate, and at the end of 48 hours produced 100,000 eggs, which yielded 98,000 fry. The shad dies very quickly after capture and is immediately respon- sive to electrical storms, the catch of seines and nets of all kinds falling off promptly when a thunderstorm develops. Even in seines already laid out in the water, with lead line on the bottom, there is an appre- ciable decrease in such event. On the Delaware River, May 29, 1887, nearly 50 per cent of the shad eggs on board the steamer Fish Hawk perished during an electrical storm which continued from 6 p. m. to midnight. There were 4,481,000 eggs with embryos well formed, and without perceptible change in water temperature 1,918,000 were killed, many turning white by 8 p. m. Heavy freshets cause an abrupt suspension of fishing, but the effect of a single freshet is usually temporary. The shad which have gone above are backed down before the muddy water, but reappear upon its outward passage. An occurrence of this kind will effect a great increase in egg receipts if the water temperature before muddy water comes is suitable. The shad that were scattered above being thrown back in a body, reascend in a body. A season of clear water is undesirable both for fishermen and hatching work, as the fish see the nets and avoid them, gill nets being put out only on the night tide and half the fishing being thus lost. The water MANUAL OF FISH-CULTURE. 133 should be discolored enough to prevent the fish from seeing the nets, but not thick, say from 10 to 20.* An occasional freshet reduces the temperature and prolongs the season; however, with an equal number of fish in the rivers, clear water is probably more advantageous for natural increase, as a large proportion of naturally deposited eggs must perish from suffocation under the mud in seasons of freshet. THE WEATHER AND SPAWN. The development of eggs within the ovaries is hastened by heat and retarded by cold. In a warm season ish ready to spawn are more numerous early in the season than in a cold one, and the period for obtaining them is apt to close earlier. The eggs, not only after they are deposited and impregnated, but before they leave the body of the fish, are affected by the temperature of the water, often being ‘ blighted” or ‘rotten ripe.” This phenomenon was observed as far back as 1873, It oceurs on the water reaching 80° to 81°, or with a rapid rise. On the other hand, a sudden fall in temperature has been observed to arrest natural spawning, produce blighted eggs, and to destroy those in the hatching vessels. Continued low temperature is also disastrous to fishing. An abnormally inferior quality of the Potomac River eggs was noticed during the full period of operations in 1896. The bulk of the run of shad made their appearance on a rapidly ascending temperature, and the eggs were injured within the parent fish, more than half perishing before conversion into fry. The rise in temperature was greater than had ‘been recorded in the eleven years preceding. The run of shad increased proportionately, the catch at’one seine increasing from 100 to 800 in 24 hours. A snowstorm on April 7—morning air temperature 35° F. and mean air temperature 46°—was followed by heavy frost on April 9, the morning air temperature on the last-named date being 349°. The river water on April 10 was 46°, rising to 48° on April 12 and to 71° in the afternoon of April 21, thus gaining 25° in 10 days. After April 21 the catch of shad fell off to such an extent that fishing was no longer profitable. The water of the Potomac early in March is usually of a temperature of 36° to 40°, rising to 52° to 58° about the middle of April, when the spawning period begins, and at the end of May, the close of the period, it averages from 65° to 70°. STRIPPING AND FERTILIZING THE EGGS. In stripping the eggs the shad is lifted with the right hand and caught above the tail with the left. AJI slime and loose scales are removed by going over the fish two or three times in quick succession with the right hand. The head is carried to the left side under the *The condition that permits the discernment of objects at a distance of 10 to 20 inches beneath the water surface, the method of registration employed by the Wash- ington (D. C.) aqueduct office. 134 REPORT OF COMMISSIONER OF FISH AND FISHERIES. arm and there retained by the arm, the tail being bent slightly upward with the left hand. When the fish is properly adjusted its head is nearly concealed. The fish is held firmly over a moist pan, and with a moderate downward pressure of the right hand the eggs will flow freely if mature. The strokes are continued until there are signs of blood, which usually accompany the last eggs. The fingers should not touch the gills of the fish, as laceration of these organs causes a flow of blood injurious to the eggs. Two fish may be stripped into each pan. As soon as the spawn is all obtained, the shad is discarded, it being impossible to preserve the life of such a delicate fish, even with the utmostcare. But though it has slight tenacity of life when taken from the water, the shad is a very muscular fish, and if not firmly held it will flounder and splash in the pan of eggs and probably throw a large proportion out and damage some of those that remain. The first half teaspoonful of eggs should be pressed out into the palm of the left hand and inspected. Skilled operatives can usually discern ripeness by general outward appearance. A slow and yet almost positive test consists in running some of the eggs into water, when, if dead, they will have the appearance of boiled rice. But bad eggs are sometimes beyond the detection of the most skilled fish- culturists. If the eggs are white, opaque, or of milky appearance, the fish is put aside. Immature eggs are white, small, and adhering in clots; or they may be transparent and yet unyielding to pressure. The former are valueless, while the latter can sometimes be utilized by putting the fish aside to soften. Both ripe and green eggs sometimes occur in the same fish, but only expert operatives can hope to take the one and leave the other. If eggs are mature, but little pressure is necessary to start them, and if not, they are only injured by squeezing, and will either not flow at all, or will come away with difficulty in clotted masses and generally with a little blood. After the spawn is taken away, the fish has a soft and flaccid appearance about the abdomen, which after natural spawning becomes contracted and drawn up, taper- ing slenderly toward the tail. Eggs of the best grade may be impaired by intermixture of overripe or green ones, lumps of milt, tissues of the sperm sac, or fish scales. The overripe and unfertilized ones can be discarded, and a tiny net, an inch square, or a straw or twig, may be used in removing foreign substances. The spawn-taker should clean the eggs before delivering them at the hatchery, and no subsequent care can compensate for his neglect. Experienced men rarely bring in bad eggs, unless as a result of vari- able and unfavorable weather conditions. To obtain the milt the spawn-taker catches the fish by the back, taking hold of the under side with the right hand. Without relaxing pressure at any point the milt is forced out with the thumb and fore- finger. Good milt is so thin that it flows in a steady stream, and from some fish it can be ejected widely over the surface of the eggs, but in MANUAL OF FISH-CULTURE. 135 fish which have been dead some minutes the milt is lumpy and flows only in drops.