SH 151 
 .P13 
 Copy 1 
 
 '^94 
 
 [AKXICLE 19.— EXTRACTED FKOM THE BTTLLETrN OF THE U. S. FISH COMMISSION 
 FOR 1894. Pages 289 to 314.1 
 
 FEEDING AND REARING FISHES, PARTICULARLY 
 TROUT, UNDER DOMESTICATION. 
 
 BY 
 
 WILLIANI K. F»AOE. 
 
 WASHINGTON: 
 
 GOVERNMENT PRINTING OFFICE. 
 
 1895. 
 
002 860 305 8 
 
 i 
 
[ARTICLE 19.— EXTRACTED FROM THE BULLETIN OF THE U. S. FISH COMMISSION 
 FOR 1894. Pages 289 to 314.] 
 
 FEEDING AND REARING FISHES, PARTICULARLY 
 TROUT, UNDER DOMESTICATION. 
 
 BY 
 
 AVILLIAlVr K. PAOE. 
 
 ^^v 
 
 WASHraCrTON: 
 
 GOVERNMENT PRINTING OFPirE. 
 
 189 5. 
 
SM 151 
 
 \ 
 
 .P/3 
 
f^f 
 
 I'J.-FEHDING AND REARING FISHES, PARTICULARLY TROUT, UNDER 
 
 DOMESTICATION. 
 
 By WILLIAM F. PAGE, 
 Suptrintinilent of Vniled States Fish Commission Station at Neosho, Missouri. 
 
 ARTIFICIAL FOOD. 
 
 lu the summer of 1893 I preseuted a paper at the Chicago meeting of the Americau 
 Fisheries Society umler the title: Plant Yearlings Where Needed. A jwrtion of the 
 paper contained a summary of some studies which I had made on feeding and rearing 
 fishes. The present paper is an ehiboration of that summary by adding the results 
 of further study and investigation. 
 
 To the fishculturist striving to improve methods and results the importance of 
 the question offish food can scarcely be exaggerated. Aside from tlie interest on the 
 cost of the plant and pay of tlie necessary employes, it is the principal fixed charge, 
 and in most cases the only item of expense capable of reduction, or, what amounts to 
 the same thing, the most promising field for obtaining better results for the outlay. 
 
 I address myself particularly to those fishculturists who are engaged in rearing 
 fishes to be sold for food, and to those who see the necessity for planting large fish iu 
 certain waters intended to be stocked. The paper will have little interest for those 
 who dispose of their fisli as fry. To the former class the data, if not the deductions, 
 must possess some value. 
 
 Nowhere in the literature of fish-culture obtainable at the general book stores 
 can the prospective investor find an answer to the natural question, Flow much will 
 it cost to raise a pound of trout? unless we except the statements made in the 
 concluding chapter of Domesticated Trout, a part of which was written twenty-two 
 years ago, and the remainder in 1890, statements which, I think, Mr. Stone would not 
 care to guarantee today.* In 1804 Mr. Francis Francis wrote: 
 
 Doubtless some kinds of food agree with them [trout] far better thau others. 13ut we know very 
 little on this branch of the subject. It is dreamland to us, with very little ascertained waking reality. 
 Few experiments of any note have been tried iu the feeding of fishes, this being as yet almost untrodden 
 ground. 
 
 This remark is as true to-day as when written, thirty years ago, and stands as a 
 monument to the want of progress among American fishculturists. I say American 
 fish-cidturists, for fortunately the Europeans have progressed iu this direction. 
 Because over two decades ago a flsh-culturist, groping in the dim light of a closely 
 shuttered house illuminated by a single bull's-eye lantern, killed his trout with a diet 
 of milk cm-d, and another expert, with as much (or as little) light in the house and on 
 
 * In the Transactions of the American Fisheries Society for 1892, Mr. F. N. Clark presents some 
 calculations ou the cost of raising yearling fish, and in the United States Fish Commission Bulletin 
 for 1893, page 228, Mr. C. G. Atkins gives some siraihir data; but neithor of them reduces the cost to 
 pounds of tish, without which, for tire purposes of this discussion, the data possess little or no value. 
 
 289 
 
 F. C. B. 1894-19 
 
290 BULLETIN OF THE UNITED STATER FISH COMMISSION. 
 
 the siibjet't, killed Ids fry with the yolk of hens' eggs, the law was laid down, "You 
 must not use curd or heus' eggs for fish food," and these two really valuable articles 
 were placed on the blacklist. Unfortunately, with all our vaunt of being the most 
 advanced of the world's nations in lish-culture, we are so conservative that it rarely 
 happens that an article which once finils itself on the list of prohibited foods receives 
 a second trial. As a matter of fact, one of the best experts in the world to-day, one 
 who makes the business pay a handsome return on the money invested, Sir James 
 Maitland, of Scotland, as far back as 1878 was using fifteen dozens of hens' eggs 
 daily. Again, one of the State lish commissions west of the Mississippi liiver depends 
 la,rgely upon curd as a trout food.* Their work will be shown to compare favorably 
 with that of other places where these cheap articles are interdicted. 
 
 Another article proscribed by one of the books on fish-culture is to-day almost the 
 sole food of one of the best-paying private hatcheries in America. These instances 
 are stated to show that the rules laid down in the text-books are not in all cases reliable, 
 having been too fre(iucntly drawn from a single Uly conducted experiment. Scarcely 
 any of the writers have anything to say on the really important (luestion. How much 
 food is required to produce a given result? Nowhere in the English books are data 
 and rules given which would enable one to calculate with any degree of exactness the 
 amouid of food needed during a given period for a given number of fish. One impor- 
 tant use of su(!h knowledge would be the calculating of a periodic supply of food for 
 some hatchery situated away from the lines of easy and cheap transiiortation. Should 
 the feasibility be demonstrated of the preparation, at the base of cheap sup])ly, of an 
 artificial food to be i)reserved and shipxjed in large quantities by freight to off-lying 
 hatcheries, the question would naturally arise, How much will be needed during the next 
 six or twelve moidhs? The early experimentalists contented themselves with saying 
 that such and such things made safe, cheap, and economical foods (in nearly every 
 case having reference to liver, heart, and lungs of animals), and that such and sucli 
 were poisonous to the fish, and quietly ignored the question of definite quantities. 
 
 The fact is that there is scarcely an article in the entire gamut from curd to horse- 
 flesh that may not be fed to trout with perfect safety. The questions are, or should 
 be: What amount per day of a given article will be needed to produce a pound of 
 trout within a given time! Is this amount of food beneficial or harmful to the correct 
 or normal development of the fish? If harmful, can it be rendered harndess by the 
 admixture of other foods? And, finally : Can the grower for the market find a profit? 
 
 In my Chicago paper it was stated : 
 
 There are amoug flshos, iu (-ommon with other auimals, several ilietaries, sonic follnweil from a 
 matter of choice, some from necessity, ami others from ignorance on the part of the attomlant. They 
 may^ for convenience, bo thus classified: First, bare subsistence diet, merely sustaining life and 
 resulting in stunted, deformed fish, or starvation; second, healthy diet, promoting normal growth 
 and development; third, fattening diet, fitting for heaviest marketable weight; and, fourth, over- 
 fattening diet, causing a temporary or permanent 8upi>ressiou of the functions of the reproductive 
 organs, a partial or total destruction of the eyes, and inllammation of the intestines, fre(iuentlv 
 resulting in death. 
 
 A considerable percentage of American fish-culturists are to-day confining their 
 stock to the first diet, ei.ther in quantity or quality of food, and are yearly producing 
 stunted or half-starved fry which, by courtesy, are called yearlings. Dismayed by 
 their own early experiences and those of the first experimentalists in feeding fishes, 
 they have not only stricken article after article from the list of available foods, but 
 
 "Practical Trout Culture, Dr. Slack, page 123; "Curd is absolutely iioisonous." 
 
FEEDING AND REARING FISHES. 291 
 
 have reduced the quantity below the jioiiit of healthy development. One of the early 
 writers has said, with every ap])earaiice of correctness, that if the fry are starved in 
 infancy they become stunted, the l)ones liarden, and afterwards no amount of feeding- 
 will cause them to expand sufficiently to permit of growth. Unquestionably, it is at 
 this stage in the rearing of fishes (the earliest feeding of the fry) that the greatest 
 amount of damage is possible and the most lasting hurt frequently done. It is the 
 most diflicult stage in feeding and rearing, because it is at this point that intelligence 
 and fidelity are needed more than at any other time. 
 
 In the first feeding of fry it is not practicable to weigh the fry or tlieir food so as 
 to instruct the caretaker as to the allowance of food; though after the fry have been 
 taking food for some little time it is possible to determine their weight, but it is 
 scarcely probable that any except the most careful experimentalists will ever expend 
 the time and labor necessary. It is not likely that any better method for this deter- 
 mination will be devised than that of Mr. Charles G. Atkins, of the U. S. Fish Com- 
 mission. His method is as follows: 
 
 The fish are first gathered in a tiue, soft bag net, commonly one made of cheese cloth, and from this, 
 hanging me<anwhile in the water, yet so that tlie tisU can not escape, they are dipped out a few at a 
 time in a small dipper or cup, counted, and placed in a pail of water or some other receptacle. This 
 counting is generally preliminary to weighing, and in this case the fish after counting are placed in 
 another hag net, in which they are lowered several hundred at a time into a pail of water, which has 
 been i)reviously weighed, and the increase noted. With care to avoid transferring to the weighing 
 pail any surplus of water, this is a correct method and very easy and safe for the fish. — (Bulletin of the 
 U. S. Fish Commission, 1893, p. 227. ) 
 
 Mr. Atkins does not say so, but it would seem that he must deduct from the 
 increased weight the weight of the wet bag net immersed in the weighing pail. 
 
 Only judgment, experience, fidelity, and watchfulness on the part of the attendant 
 charged with the feeding will be found to answer at the time when the fish first com- 
 mence to take food ; and itnless these iiiialifications are employed the fish are either fed 
 to death or starved. Some of the rules for feeding young fry would be laughable if it 
 were not for the memory of the helplessness of the fish. A rule at one hatchery is to 
 give them all they will hold; another acfpiaintance says keep them hungry all the 
 time. There are few happy mediums in practice. Years ago the idea was dissemi- 
 nated that any clever youth of ordinary capacity could safely be intrusted with the 
 care and feeding of fishes. Ihi fortunately the idea is not yet entirely eradicated. 
 They are short-sighted managers, blind to the principles of protection of animals from 
 cruelty, who leave this most important branch of the work in the hands of any except 
 the patient, intelligent, skilled workman. 
 
 Not all cases of semistarvation and stunting have resulted from the causes 
 mentioned — ignorance or fear on the part of the attendant. Cases have fallen under 
 my observation where, from various causes, the desired food, either as to kind or 
 (piality, was not obtainable. Again, some fishes, particularly brook-trout fry, will 
 persistently decline the most dainty and delicately prepared foods. My own opinion 
 is that when a lot of fry is found acting in this manner the best thing the culturist 
 can do for himself is to get rid of them at an early day. They will never make tine 
 fish. * Several reasons have been advanced to account for this peculiarity on the 
 
 * In this connection the question presents itself: May we not from this find a possible reason 
 why in certain streams, presenting a fair al)nndance of food, we never find trout al)ove fingerlings in 
 size. I, of course, suppose that in nature, as well as in artificial fish-culture, there are cases where 
 the young, from some cause, will not eat, and it is more than probable that in many lots of fish 
 hatched naturally a large percentage never find any food, or find it too late to prevent or arrest the 
 stunting process. Once stunted, always stunted. 
 
292 BULLETIN OK THK UNITED STATE*? FISH COMMISSION. 
 
 part of certain lots of trout, none of wliicli are entirely acceptable. One writer* 
 asserts that at tlie time of the absorption of the sac the fry rises iu search of natural 
 food, and if he does not fiud it he is compelled to take the artificial food prepared for 
 him, and the difiQculty of adapting his stomach to this food results iu a loss which 
 varies from 50 to 75 per cent. 
 
 Another lish-culturist says that they fail to assimilate the artificial food and die. 
 In passing, I hope to be pardoned for asking if the trout fry in the feeding troughs 
 offered artificial food when nature demands an aliment, even granting for argument 
 that they can not always assimilate it, are not iu better position to fight the battle of 
 life than the trout fry in the streams, either hatched or planted there, where they too 
 frequently find an entire absence of food, ibr we know that streams are as frequently 
 barren of natural food for trout fry as the streets of cities are barren of food for 
 children. They live and reach a certain phase of maturity, but the product too often 
 falls short of expectations. 
 
 At one large establishment where the yearling fish have for a number of years 
 been abnormally small the trouble is thought to be due to prevailing low temperature 
 of water. This, in a measure, may be true, for it is a generally accepted opinion that 
 trout will not readily take their food on cold and cloudy days, and it is not unreasonable . 
 to suppose that the same cause would prevail in water of a constantly low temperature. 
 My own observations lead me to believe that, outside of the spawning season, properly 
 trained trout will eat as greedily during a snowstorm as during fair weather. 
 
 To whate\er cause due, it must be admitted by every candid and impartial observer 
 that thousands of trout are annually raised which in size fall short of a commensurate 
 return for the time, interest, and money expended. 1 hope to show that a partial 
 correction is possible by the use of an adequate quantity of proper food. Private 
 fish-culturists, selling yearling fish at so many ilollais per thousand, are more than any 
 others interested in making this correction. Information is beginning to be dissemi- 
 nated on this subject, and the purchaser, who a few years since was willing to pay 
 fancy prices for that most meaningless and illy defined of all salable products — year- 
 ling trout — is now commencing to ask, "Of what size are the fish 1 " It seems to me 
 that it would be rational and fairer to all parties to establish a weight per thousand 
 and grade the xjrices up or down as the weight rose above or fell below the standard. 
 
 The importance of making such correction as above suggested is apparent, for if 
 at times we are stocking streams with stunted fish we are antagonizing one of the 
 hopes and claims of fish-culture, namely, the improvement of existing species. I 
 care not how carefully the breeders may be selected, how minutely all the essentials 
 of imiiregnating, liatching, and transporting receive attention, the resulting adult 
 fish will never be of large size and. fine quality unless the fry have been properly fed; 
 and it is probable tliat if these fry have been stunted their progeny will be stunted. 
 The progressive and enlightened cattle-breeder looks cloisely to it that those individuals 
 which are to perpetuate his herd have received proper feeding and acquired full and 
 normal development; and if by chance a runt is among the herd, it is set apart from 
 the breeders. For the same reason we should not allow stunted fishes to cuter into 
 the brood stock or into streams. 
 
 Against the danger of under feeding there should be little cause to warn the 
 culturist engaged in gxowing for the market. But because I have known such cases, 
 
 • Mr. Uerschel Whitaker, Trauu. American Fisheries Society, 1892, p. 96. 
 
FEEDING AND REARING FISHES 293 
 
 the warning is distinctly given to the [)rivate fish-cultnrist. Tlie greatest draw- 
 back against raising large tront in a given time (possibly sari)assed by an improper 
 selection of breeders) is an improperly jjrepared food given in starvation rations to 
 the fry. " As the animal is, so to speak, made daring its early age, and as during 
 this period its assimilating organs acqnire their strength and their power of absorp- 
 tion, a young fisli which is insutticiently fed not only grows very slowly, but will never 
 become a fine fish."* Time was, and unfortunately is yet with too many, that canni- 
 balism was the only danger feared from fry on short rations. Cannibalism was a very 
 good bugbear, but the true danger does not lie there, as it is always capable of correc 
 tion in a short time. 
 
 The discussion of the second and third diets mentioned will be passed over for 
 the present and we will proceed to look at some of the ill effects of the fourth, over- 
 fattening diet, "causing a temporary or permanent suppression of the reproductive 
 organs, a partial or total destruction of the eyes, and infiammation of the intestines, 
 frequently resulting in death.'' Nearly every flsh-culturist of exjierience has seen 
 the two latter evils, "pop-eyes" and "inflamed intestines;" whilst many have observed, 
 without knowing the cause, the retardation of the genital organs of the tishes. It 
 seems fairly probable that the causes known to affect the breeding of other animals 
 will in like manner influence the breeding of tishes. It is a recognized principle 
 among stock-breeders that an overrapid accumulation of fat is followed by partial 
 or total sterility, just as conversely a removal of the genital organs is always followed 
 by a rapid accumulation of flesh. It would seem that the two processes are intimately 
 connected, and that an excess in either direction is at the expense of the other. The 
 complaint has not infrequently been made: "My fish grew finely, attained a remark- 
 able growth, and I fully expected a large number of eggs this season, but got very 
 few." It rarely or never occurs to such complainants that the want of eggs was due to 
 the exceptionally tine growth. I have in mind a hatchery where the growth of brook 
 trout was such that many of them lost their eyes. Eggs were obtained in fair quan- 
 tity, but they were of such low degree of vitality that the season was counted a failure. 
 When these fish were marketed their ([uality was graded low. More than twenty 
 years previously Dr. Slack had noted a similar occurrence. In his book (Practical 
 Trout Culture, p. 121) he recounts the following: 
 
 A wealthy gentleman of a neighboring State constrncted a well-appointed fish farm, with well- 
 stocked ponds. To his surprise, during the spawning sea.sou but few eggs could be obtained aud bur 
 a small percentage of these conld bo iuipregnateil. We were consulted in regard to the matter, and our 
 first look at his tishes showed us plainly the cause of the trouble. The tishes were enormous, the 
 bodies greatly swelled, the whole cavity of the abdomen being filleil with layers of fat. It appeared 
 that the proprietor had for over a year fed them twice a day all thev could eat, and the result was, as 
 might have been expected, l>arreu ami unhealthy fish. 
 
 If ever artificially reared trout sell on a parity witli wild trout — and there is no 
 reason why they can not be made to do so — it will not be the overfed, pop-eyed, liver- 
 leeking fish, which will produce the result. The danger of overfeeding is just as 
 distinct and as much to be avoided as that of underfeeding, though obviously the 
 evil effects will be less lasting and moic restricted in results. 
 
 Let us now turn to the second classification, " healthy diet, promoting normal 
 growth and development." By healthy diet I mean not only the i)roper amount of 
 food per day, but a food composed of proper constituents. It has been before iuti- 
 
 *C. Raveret-Wattel ; U. S. Fish Commission Bulletin, 1887, p. 210. 
 
204 BULLETIN OF THE UNITED STATES FISH COMMISSION. 
 
 mated that tbe writers on fisli-culture have beeii vague in dealing witli thi.s subject. 
 A few (inotatious will serve to make this point clear: 
 
 This iiuautity varies with the season, tbe (piality, the quantity, anil temiieratureoC the water, and 
 other eirennistances, and can not be stated definitely. — (Doniestieated Trout, Livingston Stoue,i). 2o<j, ) 
 
 Under favorable tircnmstances 5 pounds of meat food may be eonsidered an eipiivalent for a 
 pound of tront growth, with 2 and 3 year olds. For any given quantity of 2 or 3 year olds 1 per 
 cent of their weight may be regarded as an adequate average daily ration the year round. Two and 
 three year olds will double their weight annually, and can bo made to do so in the six months from 
 May to September by extra care and feeding. — (Domesticated Trout, p. 26.").) 
 
 As to the quantity of food necessary for a given number of trout. This is dllificult to give 
 exactly, as it will vary with the size of the fish and the season of the year, more being rec|uired in 
 moderate weather than wluu it is very hot or cold. For 1.000 three y<!ar-olds. about.'i pounds of liver 
 or lights per day. — (Trout Culture, Seth Green, p. .51.) 
 
 When six months old a bowlful of curd, <liluteil witli water, will answer for 1,000 trout fry. — 
 (I'rout Culture, Seth Green, p. 38.) 
 
 Since our stock of fi.shes attained its present size we have never been able to obtain as large .a 
 supply of food as we would desire ; yet we find that our stock fishes, weighing in the aggregate about 
 a ton (2,000 pounds), thrive upon .")0 pounds of lights a week, fed tboui in equal proportions on 
 alternate days. As an average 50,000 young will require, when 6 months old and well supplied with 
 maggots, about a i)0und of chopped heart thrice weekly, though the amount varies greatly.— (Practical 
 Trout Culture, Dr. J. H. Slack, pp. 121 and 125.) 
 
 The (|uautity of food required is also large (for 2-year-old trout). Three pailfnls of chopped 
 horse are given daily to pond 15, which yields from 20,000 to 22,000 each season. The food is measured, 
 not weighed, lint each pail holds 14 pounds. — (History of Howietoun, Sir .Tames Maitlaud, pp. 73 
 and 74.) 
 
 When trout are raised in ponds of the dimensions 1 have given it is cviilent that little or no 
 dependence is to be placed on natural feed, such as files and their larva'. Hence the necessity of 
 providing cvirds or liver .and lungs of animals, at prices that will not cause too great an expenditure 
 for the v.alue of the cro]). I have found that tlie curd from f be ULilk of one cow, which gave 14 (piarts, 
 would feed bountifully 1,000 or 1,200 trout averaging five-eighths or three-quarters of a pound, the 
 smallest being 7 inches long and the largest from 2 to 3 pounds in weight. — (American Fish Culture, 
 Thaddeus Norris, p. 74.) 
 
 These quotations, carefully selected as the cx|)ressions of the five most generally 
 read English writers on flshcnlture,* show how little definite and accurate information 
 is recorded on the vital question of what should constitute a proper ration for a given 
 number of trout. Sometimes the number of fish is stated, sometimes their age, in cue 
 instance the approximate weight is given, and only one lOnglish writer has had the 
 courage to approach scientific accuracy. But, alas! His formula is made to ap])ly 
 only to fish 2 and 3 years old. The fry .and the lish more than 3 years old are not 
 provided for. 
 
 The amountof Ibod necessary for the maintenance in gooil health of a given lot of 
 fish must, as with any other animals, be in direct ratio to their weight, not their age. 
 
 * From writers of other nationalities the following quotations may be acceptable: 
 By experiments M. Lugrin lias ascertained that a. basin » » » may contain 20,000 
 young fish from 8 to 12 months old, or 3,000 two-year-old triuit having an aver.age weight of 250 grams 
 (J,',, or a little more than one-half pound). These 20.000 young fish, or 3.0f0 trout, cmisume about 
 22 pounds of small shrimps per day. — (The IMscicultural establishment at Groiuaz, France; by 0. 
 Raveret-Wattel, Bulletin I'. S. Fisli Conimissiou. 1S,X7, ]i. 200 ct seq.) 
 
 At Howietoun it is on the weight (onc-filticth of ihe living weight) that is determined tbe food 
 to be given, a method which appears more scientific and at tbe same time more practical than that of 
 feeding them without regard to age or develoiuuent. — (Notes of M. Mespies, proprietor of the fish- 
 cultural establishment at Nanteiiil-cu-Vallee, France.) [I h.ivenot been able to find (his formula of 
 one-fiftieth of the living weight aiiywherein the History of I lowietoun, and I siipposethat M. Desjircs 
 must have received the information privately. I am fully in accord with M. Despres in his criticism 
 on the value of this formula.] 
 
FEEDING AND REARING FISHES 
 
 295 
 
 To state that 20,000 fisli require three buckets of food per diem, without stating the 
 weight of the fisli, is iiisuHii-ient. 
 
 One of the first things to impress itself upon the attention of the student of tins 
 question is the wide and almost unaccountable variation in the size and weight 
 acquired by fishes of the same species under different hydrographic and climatologic 
 conditions. In some instances this variation amounts to 700 per cent. Compare the 
 weights of yearling trout raised m Colorado and Missouri. Who would say that 
 1,000 of the Missouri trout should be restricted to the same daily rations as a like 
 number of like fish in Colorado? Elsewhere I have said that the Colorado trout could 
 not consume the allowance of the Ozark (Missouri) trout, and that the Ozark trout 
 would stunt or starve on the Coiorado allowance. Better results will be obtained 
 when fish-cultuiists realize that fishes must be properly and plentifully fed in their 
 infancy and that their allowance of food, regardless of age, must i>e in constantly 
 ascending ratio with their increasing weight. 
 
 In the first study of this question I early found tho lack of definite data in the 
 English writings. Correspondence was instituted to ascertain the general practice. 
 For convenience of comparison and study a condensed tabular statement of the 
 replies received is here presented : 
 
 Food and growth of trout. 
 
 Nanio ami location of 
 estublisbmeut. 
 
 Solwn^-, Sootlnad 
 
 Howit'toiiii, Scotland 
 
 triiiltord. Eniilaud 
 
 Hasleiuere. England 
 
 Vivero. Mexico 
 
 La Condcsa, Mexico 
 
 Cold Sprius Ponds, N. H.. 
 
 Troutdalo Farm, Ark 
 
 Willow lirook. Minn 
 
 Aunin's Hatclicrv, Caledo- 
 nia, N. Y. 
 OldColonv, rivmontli,Mas,'i 
 
 Stale Hat.lK ry, Nevada 
 
 Stale Hatclicrv, Kcbraska. 
 Duluth Station, U, S. F. C 
 Leadvillo Station, U. S. F. C 
 NorthviUe Station, U.S,F.C 
 Wytlieville St,at'n, U.S,F.t; 
 Ueosho Station, U. S. F, C 
 
 Elcva 
 tion 
 
 above 
 sea 
 
 level. 
 
 ■■'""''■''l <ion.s, in 
 
 -^^^r 
 
 150 
 300 
 
 200 
 7. 6011 
 6,500 
 500 
 COO 
 685 
 690 
 
 50 
 4,660 
 1,100 
 
 602 
 9.640 
 
 600 
 2, 300 
 1,041 
 
 50 
 
 50 
 
 50 
 
 49-56 
 
 57 
 
 68-70 
 
 35-76 
 
 59.5 
 
 40.5 
 
 48 
 
 50 
 45 
 50 
 
 36.3 
 44.3 
 ,53 
 58 
 
 1,16 
 
 .66 
 
 'rv sm'll 
 
 . .'do . 
 
 4 
 
 2.5 
 10 
 
 .12 
 
 .14 
 
 .47 
 
 1.87 
 
 Character of 
 food. 
 
 Animal 
 
 do 
 
 do 
 
 do. 
 
 do 
 
 do 
 
 do 
 
 > anim'l § veg 
 
 Anim.al 
 
 do 
 
 Natural food 
 
 present in 
 
 ponds. 
 
 Length 
 of aver- 
 age year 
 ling 
 trout. 
 
 Yes 
 
 do 
 
 Abundant . 
 do 
 
 .do... 
 .do... 
 .do... 
 .do... 
 .do... 
 do ... 
 .do... 
 g.Janlm'l 
 
 No 
 
 None 
 
 Abundant. 
 
 ....do 
 
 Some 
 
 Im'nse qu'n'ty 
 
 Yes 
 
 Limited . . - 
 
 Considerable 
 
 Scarce 
 
 do 
 
 do 
 
 Inches. 
 2. 5 to fi 
 
 3,5 
 4 to 10 
 4 to 10 
 
 6 to 7 
 
 7 to 8 
 
 6 to 7 
 
 7 to 10 
 
 5 
 3,25 
 
 6 
 
 4,5 
 
 5 
 
 2.5 
 
 to 6 
 
 4.5 
 
 5,5 
 
 Weight per 1.000 average 
 yearlings, in pounds. 
 
 No tests made. 
 No tests made. 
 
 75 
 tl5 
 
 ;90 
 
 50 
 
 70 
 
 10 
 
 560 
 
 •250 
 
 80 
 
 tl5 
 
 150 
 t20 
 
 tl5 
 
 75 
 
 90 
 
 No tests made 
 50 
 80 
 
 5 80 
 
 60 
 
 51.8 
 
 50 
 
 80 
 
 6 
 
 §40 
 
 *This weight was for flab 15 mouths old. My experiments in the spring of 1883 demonstrateil that rainbow trout increase 
 their weight enormously in the fourteenth and fifteenth months. In proportion to the increase at Neosho the Troutdalo 
 (Mammoth Spring) trout, at 1 year old probably weighed 82,27 pounds per 1,000 fish, 
 
 t Mr, Aniiin says: "I have been very careful that my answers have been correct, anil not magnilied." 
 
 : These answers are given as of May 1, I should say that the fish were yearlings past. and. .iuilging from the length of 
 the fish, very highly fed, 
 
 5 Determined by the weights of specimen fish fnrnished to be cast for the World's Fair at Chicago. Fish furnished by 
 the Neosho station for the same purpose ran 390 pounds for brook, 200 pounds for Von Behr, and 140 pounds for rainbow 
 trout (per 1,000 yearling fish). 
 
296 BULLETIN OF THE UNITED STATES FISH COMMISSION. 
 
 Tlie difference in locality, elevation above the sea, and mean annnal temperature 
 of the water at the hatcheries is quite varied, hut not more so tliau the daily rations 
 given. As for the results — the weight of the yearling fish — the data as given do not 
 admit of a too close comparison, some of the fish having been weighed at 10 months 
 old and others at 1.5 months old. 
 
 However, a study of the table does show that there is not only a decided lack of 
 harmonj' between the practice or methods of feeding followed at the various estab- 
 lishments, but that some are giving an inadequate (]uantity of food and others are 
 feeding far in excess of the needs. For instance: Leadville Station gives but 2 ounces 
 of animal food ])er day per 1,000 yearling trout, while the Willow Brook Hatchery, 
 of the Minnesota Fish Commission, gives eighty times as much to the same number of 
 fish. The quantity of food used at the Leadville Station is the smallest for which I 
 have any retui'n, and it is not surprising to find that the fish grown there are smaller 
 than at any other hatchery in the United States. The next smallest is the Howie- 
 toun Fishery, of Scotland, where the ration is but two thirds of a pound and the 
 weight of 1,000 yearling fish (Loch Leven trout) but 10 pounds. 
 
 When the very small size of the fish produced at Leadville first came under my 
 notice I was of the opinion that the extreme altitude of the place might in some way 
 (possibly l)y reason of the low teinpei'ature of the water consequent upon such gxeat 
 elevation) be a controlling factor in producing such a slow growth. So firmly was 
 this idea fixed, that when the returns from the Mexican hatcheries were received I 
 requested a retesting of tlie weights. Not only was the weight as first given corrobo- 
 rated, but a sample of the food used was furnished. In that sample of food, " mos- 
 (piitte" {Corizti femnrata) was found the secret. It was a correct food, unfortunately 
 at present beyond the reach of American fisli culturists. 
 
 Seeing, then, that the laws of the text books and the general jiractice ai'e so 
 variable, vague, and unsatisfactory, let us see what may be determined by analogous 
 reasoning from the established laws of dietetics for other animals. 
 
 Before entering ujion tliis branch of the subject the reader is requested to bear 
 in mind that fish are cold-bloodeil and will never need — in fact, M'ould be overburdened 
 with— as large a proportion of heat-producing foods as are needed by the warm-blooded 
 animals. Being cold blooded, they have no body temperature to maintain, and so do 
 not require in so large a degree the rich hydrates of carbon needed by the warm- 
 blooded animals. Again, in small ponds, where the very largest per cent of the food 
 is supidied artificially, the work of the fishes in procuring a livelihood is reduced 
 to a minimuiu, and this will also be found a factor in determining the character of the 
 food to be supplied. 
 
 Animals for which laws of dietetics have been establislied most nearly resembling 
 the condition of fishes under domestication are cattle and men not at work. But no 
 perfect parallel ciin be drawn between these classes on account of the body heat to be 
 maintained on the one hand ami its absence on the other. It seems that the average 
 man, passive or at lightest work, requires, according to the various authorities, solid 
 substances ranging from '20 to 44 ounces per day.* Assuming the average man to 
 weigh 130 pounds, the aveiagc of the allowance of the authorities would be l.t per 
 cent of the weight of the man. Dr. M. (i. Ellzey, formerly professor of agriculture at 
 
 • Billiugs's National Medical Dictionary, p. xxxix; Flint's Text-Book Human Physiology, pp. 191, 
 192; Marshall's Outluies I'liysiology, p. 899. 
 
FEEDING AND REARING FISHES. 297 
 
 tlic Virginia AgricTiUural and Meclianif.il College, is my authority for saying tliat 
 "about li per ceut dry food substances of the live weight is reckoned good keep for 
 mature live stock." 
 
 It will be noticed that these allowances are for dry substances only. In au 
 attempt to make a comparison between tlie food allowances for men and cattle and 
 fishes the liquid substances have piirposely been omitted. This is impossible of 
 calculation for the fishes. It will vary constantly with the character of the water, 
 the soil over which it drains, and the season of the year. It may roughly be assumed 
 that the sustaining elements of the coffee, tea, milk, etc., entering into the food of the 
 warm-blooded animals is replaced or compensated for by the insect life present to a 
 greater or less extent in or over most waters. 
 
 A study of the foregoing table and quotations giving the feeding methods followed 
 at the various fish-cultural establishments shows that the average of the food allowance 
 is (ii iier cent of the weight of the trout. Last year I expressed the opinion that this 
 allowance was in excess of the requirements. This judgment was possibly hasty, 
 for it is to be noticed that in every instance the amounts are for wet foods; that is, 
 for liver, meat, curd, etc., in a more or less moist condition. The limited data at my 
 command shows tliat 1 pound of liver contains 24 per cent of dry substance; 1 pound 
 of horseflesh contains 23 per cent of dry substance, and 1 pound of curd contains 45 
 per cent of dry substance. From tests I find that 1 pound of mush made from ship- 
 stutf, or shorts, contains 28 per cent of dry substance. Hence we would have as the 
 average 2.J per ceut of dry substance given to fish as against Ih per cent aUowed cattle 
 and men not at work. I think it will be admitted that this is too much. Not only is it 
 contrary to analogy, but the experience of the Neosho Station has proven, to my 
 satisfaction at least, that it is in excess of all requirements. In the year which gave 
 us the highest degree of satisfaction the food allowance was 3 per cent wet sub- 
 stances, or 0.75 per cent dry substances. Tlie trout at one year old in that season 
 attained a length of inches and a weight of 51.86 pounds per 1,000 fish. On page 
 300 will be found the schedule of the food allowance for these fish during each month 
 of the year reduced to a daily allowance per 1,000 fish. 
 
 From the foregoing, and from other observations, I am of the opinion that 1 per 
 cent of the live weight per day of dry substances will be found ample for front, and 
 that an amount much in excess of this would be prejudicial to tlie development of 
 the fish. But it must not be supposed that this allowance of any or all substances 
 will be found to produce the desired result. As before intimated, the contrary will 
 sometimes happen. Man could exist but a short time on lA per cent of his weight on 
 bread or meat alone. Not only this, but it has been pointed out that all food substances 
 vary, in the quality of their (jonstituents, with the soil and season. No matter how 
 perfect the premises and how careful the reasoning, safe laws of dietetics, for man 
 or fish, will be found to require a great degree oi' elasticity. 
 
 Certain conditions are necessary to make an artificial food generally acceptable. 
 The supply must be convenient and certain; the cost must be such as not to entail 
 too great an expenditure for tlie value of the cro]i of fish; it should be a substance of 
 easy and rapid preparation, and, above all, the chemical composition, or proportion 
 of nitrogenous and nonuitrogenous constituents, should be in accordance with the 
 requirements of the fishes to be fed. In determining the food to be used at any 
 hatchery all of these factors must be considered in connection with the conditions of 
 
298 BULLETIN OF THE UNITED STATES FISH COMMISSION. 
 
 the local market. Tlie one element of food wliicli lias most generally been found to 
 fill these conditions is liver. It was probably the most fortunate accident in the 
 history of lish culture that the circuuistances of the first three conditions forced the 
 uttentiou of the early cultiu'ists to liver. Its adoption may be viewed in the light of 
 a lucky accident, for in those days only the first three conditions were recofjnized, and 
 the fourth and most important condition, the proper combination of tlie elements 
 with a view to the requirements, was not cousidei-ed by the flsh-culturist. To-day, 
 unfortunately, it is but slightly understood. In substantiation of the view of the 
 value of liver the reader is referred to Prof. E. Wolff's table of percentage of nutritive 
 substances used as fish food.* From this table it appears that the chemical compo- 
 sition of liver (and hearts, lungs, and brains of oxen) more nearly approximates that 
 of insects and their larvst^ than does any other article of animal substance which has 
 yet come into use. 
 
 In Nicklas's Pond Culture tlie study of the food for carp is detailed fully. Nick- 
 las deduces the formula that — 
 
 The most favoraljle proportiou of nutritive substances iu carp food is Nh : Nfr :: 1 : 0.5 (or 0.6), 
 and timt < onsequeutly food containing a good deal of nitrogen is tlie best and most profitable for carp. 
 The most suitable articles for food, therefore, are blood, horseflesh, fish guano, curds, meat dried and 
 ground fine, refuse from slaughterhouses, etc. All these, however, require to be mixed with other articles 
 of food contaitiimj less nitrogen, so as to restore the proper 2)roportioi) of niitritire siihstaiices. On the whole 
 the food for the carp will have to be mixed very much on the same principle as that for cattle and 
 other domestic .animals. 
 
 The italics in this quotation are mine. When it is remembered that Nicklas's 
 formula was evolved to apply to the sluggish and slow-bi'eathing carp, and that the 
 main subject of this paper is the active and rapid-breathing trout, the emphasis will 
 be apparent. The very largest i)roportion of the nonnilrogenous elements of food 
 required by the trout (and it will be very nuich iu excess of that needed by tlie cari>) 
 is for the purpose of respiration. It is for this reason that the otherwise excellent 
 article of liver, when employed alone, has not i)roveu a perfect food for trout; and it is 
 partly from this reason that the Neosho method of mixing a large proportion of nou- 
 uitrogenous substance with the liver has secured such satisfactory results. 
 
 If the careless reader is inclined to ask. Why is not a food well adapted to one 
 kind of fish (carp) equally well suited to another (trout)? I would reuiind him that 
 whereas man in the tropics needs but the scantiest quantity of fats and oils the 
 Eskimo re(|uires 20 pounds of animal food daily.t It would be a serious error to 
 suppose that the food suited to carp is equally suited to trout, or that the food 
 adapted to trout living in a mean temperature of .55° to 65° would be the best for the 
 same fish in a mean temperature 30° lower. The very change in the rate of respira- 
 tion consequent on the change of temperature would, if the feeding was to be done on 
 the most economical and rational basis, entail a change iu the character of the food. 
 A consideration of these facts led me some years ago to adopt a mode of feeding trout 
 which has since become known as the " Neosho method." The following description 
 of the method of preparing the food and feeding the fish at the Neosho station may 
 be of interest. 
 
 » Die Teichwirthschaft. From the Lehrbueh der Teichwirthschaft, by Carl Nickliis. United 
 States Fish Commission Ueport, 1884, p. 467. Translated from the German by Herman Jacobsou. 
 t Second Voyage for the Oisoovery of the Northwest Passage (Sir John Koss). 
 
FEEDING AND REARING FISHES. 299 
 
 FISn FOOD AS PREPARED AND USED AT THE NEOSHO STATION. 
 
 The base of the food is composed of a iiiush made of "shorts," or mill middlings. 
 To this mush, according to the kind of tish to be fed, beef liver is added in varying 
 ]noportions. The mush, unmixed with liver, is fed to some kinds of lish; mixed with 
 liver to others, and for some kinds is 7iot employed. For making the mush we use the 
 best quality of shorts. The poor quality will not answer, because, like corn meal, the 
 nnish made from it is too readily soluble in the water, dividing into finer particles 
 than the fish will eat. To obviate this we have the miller mix from 5 to 10 per cent 
 of poor flour with the shorts when it "runs poor." For making the mush a large, 
 25 gallon farm boiler is tilled nearly full of clean water, which is brought to the 
 boiling point. Shorts is tliea added, about 1 gallon at a time, and thoroughly stirred 
 in. Care is taken that the shorts does not become lumpy, but has a chance to cook 
 in an even pasty mass, otherwise portions would he raw. After enough shorts has 
 been added to bring the mass fo a thick mush it is poured off into conveuieut-sized 
 pails ami allowed to cool. It has been found advantageous to allow the mush to set 
 and harden thoroughly in the pails before using. To aid this ju'ocess in the summer 
 the pails are placed in the cold running water in the hatching troughs. When 
 thoroughly set, well hardened, it is not so likely to too freely dissolve in the ponds. 
 
 To each kettlefnl, of 2."> gallons capacity, 30 pounds of shorts are used, producing 
 100 pounds of mush. To each kettle of mush, as it is being made, three to four junts 
 of common salt is added. Whilst the shorts is being added to the boding water the 
 mixture requires constant, vigorous stirring. For this purpose we use a wooden 
 jiaddle with a handle 4 feet long. Forty-five minutes is usually sufficient time in 
 which to prepare such a quantity of mush. 
 
 Four to five minutes wdl prepare a 10-pound beef liver for our work (except when 
 feeding young fry), by using a Ko. 22 meat cutter made by the l.nterpriso Manufac- 
 turing Conq>any, of Third and Dauphin streets, Philadelphia, Pa. These machines 
 are provided with perforated plates for regulating the size of the cut of meat. The 
 perforations vary from one-sixteenth to three-eighths of an inch, being ample range 
 from smallest to largest fish, except for very young fry. When trout commence to 
 feed the liver is run through the one-sixteenth inch plate, and afterwards is forced 
 through a tine-wire screen. The screening of the liver is kept up until the trout are 
 large enough to swallow the particles of meat as they come from the machine. This 
 period varies with the development of the fish, the safe period averaging about the 
 third month of feeding. 
 
 The very young trout have never been subjected to the mush diet, though it is not 
 doubted that they could be induced to eat it, but they are started and kept upon a 
 pure beef-liver diet until they are thoroughly trained to congregate for their food. 
 When the fry have been on beef liver for about two months we commence to mix in a 
 little mush, and gradually increase the proportion of mush (and quantity of food) until 
 by the time they are six months old the mush and liver may be in equal proportions. 
 jVfter that time the addition is made freely, so that when the fish are yearlings the 
 liver may be reduced to a minimum. Exigencies have arisen making it desirable to 
 economize on liver. At such times we have not hesitated to i)ut the trout on a diet of 
 pure mush. They rise to the surface for this food, sometiines meet it in the air, and 
 rarely or ever allow a particle to reach the bottom. That the fish in-oduced by this 
 diet are normal and healthy is beyond all question, and il evidence is wanted it is to 
 
300 
 
 BULLETIN OF THE UNITED STATES FISH COMMISSION. 
 
 be found in the fact that their progenitors, spawning them at 2 years old, wore raised 
 on the same diet. As yearhugs these fish averaged 6 inches long and 51.80 ponnds 
 to the 1,000 fish. 
 
 Tbe adaptability of the stomach of the trout for various foods was tested by the 
 following experiment which I conducted at Neosho in lHi)'2. On August 0, 18!»2, 
 12,000 healthy trout fry, which had up to that time receiveil the same general treat- 
 ment and allowance of food as we usually give, wei'e deprived of all animal or flesh 
 food. From that time until they were shipjicd, in February, lS!t3, not an ounce of 
 animal food was given them, and it is certain that the natural animal food which they 
 might have obtained was the very least. At the end of the year they averaged 4 
 inches in length, and an average 1,000 weighed 27.5 i)ounds. The fish were normal and 
 healthy, and though under the average for Neosho, they were above the average of at 
 least two American establishments. 
 
 The results to be obtained Ijy this method are intimated above and a comparison 
 of results may be made by referring to the table on page 2!t5 
 
 As to the cost of this method the following table shows the allowance per 1,000 
 fish from ^lay 1 (about the average time when fry are liberated as such) to December 
 31. 1 might state that at the Neosho Station liver costs 5 cents per pound and mush 
 one-fourth of a cent per pound. These prices will, of course, vary with the locality. 
 
 Daih/ nllon-ance of food, in pounds, per 1,000 rainbow trout {Xeuslio method and j'ractice). 
 
 Period of time. 
 
 During May .. 
 
 June 1 to 7 
 
 June 8 to 14 
 
 June 15 to 21 
 
 June 22 to 28 
 
 June 29 to M 
 
 JuItI to 5 
 
 July 6 to 12 
 
 July 13 to 15 
 
 Jiily 20 to 26 
 
 July 27 to 31 
 
 August 1 to 31 
 
 Seiiti'iulier 1 tn30. 
 
 OctobiT 1 to 31 
 
 November 1 to 30 . 
 December 1 to 31. . 
 
 Liver. 
 
 Mush. 
 
 .07 
 
 .30 
 
 .10 
 
 .40 
 
 .12 
 
 .48 
 
 .15 
 
 .60 
 
 .17 
 
 .68 
 
 .20 
 
 .80 
 
 .20 
 
 .80 
 
 .22 
 
 .88 
 
 .25 
 
 1.00 
 
 .27 
 
 1.08 
 
 .10 
 
 1.20 
 
 30 
 
 1.20 
 
 ..15 
 
 1.4U 
 
 .40 
 
 l.GO 
 
 -i'V 
 
 1.80 
 
 .5C 
 
 2.00 
 
 Calculations from the above table show that the food for 1,000 rainbow trout from 
 May 1 to December 31 (discarding Iractious in the totals) amounts to 75 pounds 
 of liver and 300 pounds of mush, costing in the aggregate 84.50. The production 
 for this expenditure averages 50 pounds of trout. The value of this product varies 
 with the market, and is impossible of calculation for any specified period. 
 
 In a short article in the United States Fish Commission Bulletin for 1804, pp. 71 
 and 72, may be found some additional notes on the feeding and rate of growth of 
 trout in their second year at Neosho. By reference to this article it will be seen that 
 l,.^)^ 13-months old rainbow trout made tbe remarkable gain of 241 per cent of their 
 weight in ninety days at an expenditure of 5 cents for food for each pound of trout 
 gained. At the end of sixteen months tliese fish were at tlie best marketable weight, 
 about one-third of one pound, secured at a cost, for food, of about 7.J cents per pound 
 of fish. This very rapid development of the trout during the latter three months is 
 not peculiar to Neosho. Senor Clu'izari states that the rainbow trout in Jlexico attain 
 a weight of 100 pounds per 1. ()()(> yearlings ( I ). and that -'their development in the 
 latter part of the year is very rapid." 
 
FEEDING AND REARING FISHES. 301 
 
 The trout reared at the three hatcheries where the Neosho method of feeding is 
 followed, namely, Xeosho, Mo., Wytheville, Va., aud Mammoth Spriug, Ark., are not 
 surpassed by any in the United States or in Enrope. Oidy at the Mexican hatcheries, 
 where the cheap labor and peculiar conditions enable them to collect and supply the 
 natural food in sufficient quantities, are larger trout grown in the same period of time. 
 In 1893 the method was adopted by Mr. F. N. Clark, superintendent of the Michigan 
 stations of the U. S. Fish Commission. 
 
 Stubborn as are the facts which have been presented, the mixed diet for trout has 
 been covertly attacked on the ground that trout, from the nature of their teeth, are 
 carnivorous, and that it is contrary to nature to su]tply the domesticated trout with 
 other than a purely flesh diet. If onr knowledge of dentition ever reaches any degree 
 of exactness it will show exceptions to the general law which will refute such idle 
 talk. It is a fact well known to all careful observers that — 
 
 All our common fresh- water fishes eat vegetable matter. All of them seem to be foml of iiiiilberries 
 and elderberries. Chubs, perch, eels, cats, carp (suckers) eat all grains aud the meal thereof, whether 
 whole or ground. I believe that all of the rodentia are at times flesh-eaters. Herbivora often eat 
 flesh. Hor.ses, mules, and cattle eat dry tish-scrap freely. In the case of fishes which scarcely chew, 
 the dentition does not impede a change from one sort of diet to another. The lines which separate 
 between flesh-eaters ,ind vegetable-feeders are scarcely so hard and fast as are generally thought. — (Dr. 
 M. G. Ellzey, ex-commissioner of fisheries of Virginia.) 
 
 The dentition argument against the mixed diet for domesticated trout is as 
 reasonable as that of the so-called school of vegetarians, who declare that because oiu- 
 teeth resemble those of the vegetable-feeding apes more than any other animals our 
 most appropriate food is the fruits of the earth. I have before stated that the trout 
 we feed in our ponds are domesticated animals; that the jackal and the wolf are 
 carnivorous, but the domesticated dog sickens and dies when restricted to tlie only 
 food acceptable to his ancient progenitors. It is strange and unaccountable that the 
 aveiage flsh-culturist will persist in basing all his arguments for the determination of 
 the food for fishes under domestication upon the known habits and preferences of the 
 fish in a wild or natural state. All data relating to the habits aud food of fishes in 
 nature are of the highest value to the tishculturist in determining the best conditions 
 for stocking streams, but they have no direct bearing upon what should constitute 
 their food under domestication. 
 
 Dr. James A. Henshall presented at the twentieth meeting of the American Fish- 
 eries Society (Washington, D. (\, May, 1891) a paper on The Teeth of Fishes as a 
 Guide to their Food Habits. In the closing portitm of this paper he says: 
 
 Thus, by observing tlic character and position of the teeth of tishes we have a sure and certain 
 indication of the character of their food, that is, of their principal and natural food. Of course, 
 tliere will be exceptions, but they only prove the rule. .\u herbivorous fish will occasioually swallow 
 animal food, while a carnivorous fish will sometimes swallow vegetable matter. » » » They should 
 be judged, however, by what they feed on mostly aud habitually when situated so that they can 
 exercise their choice in the matter, for change of environment may involve a change of diet. 
 
 The last sentence of this quotation strikes the keynote of a mixed diet for trout 
 under domestication. Dr. Henshall would have come nearer to the facts had he said 
 that a change of environment (and it is a wide change from nature to domestication) 
 frequently demands a change of diet. 
 
 In Forest and Stream for November IS, 1893, over the signature of Mr. A. N. 
 Cheney, is the following statement: 
 
302 BULLETIN OF THE UNITED STATES FISH COMMISSION. 
 
 One of our best-known fish-eulturists told mo of his experience in rraring trout for market on 
 mammal food. He said he hauled his liver, etc., to the iicmd in a iwo-horse wagon, and carried the 
 trout to market in a basket on his arm. 
 
 It is very i>ossible that thi.s misiiuided brother wa.s one of the best-kuowii fish- 
 culturists, but it is certain tliat lie was not one of the knowing, for, while lie was 
 employing two-horse wagon loads of liver to produce basketfuls of trout, other fish- 
 culturists were rearing them on a mixed diet of liver and mush for 8 cents and 10 
 cents a pound. 
 
 On page 49 of Seth Green's Trout (Julture is the statement that " trout are car- 
 nivorous, and will not eat vegetables of any kind that we have ever tried." This 
 statement, in exactly the same language, is repeated nine years afterwards on page 
 80 of Pish Hatching and Fish Oatchiug, published in 1879 by Mr. Green and Mr. 
 Roosevelt, commissioner of fisheries of New York. Mr. Green's efforts in this direc- 
 tion could not have been very extended. The trout at Neosho are very fond of 
 crackers (stale oyster crackers), and I have frequently given the fry a treat of boiled 
 potatoes, forced through a masher (0. V. Henis patent, which I regard as superior to 
 Sir James Maitland's feeding spoon), boiled rice, pease, and beans. 
 
 There is a statement in Mr. Green's first book (1870) touching the matter of feed- 
 ing which takes almost the form of prophecy. On page 47 he says: 
 
 Trout can be bred to any color by t'ecdiug and the use of proper ponds, and we believe that in the 
 future they will be bred to color, shape, flavor, etc., with as much nicety and certainty as the cattle 
 fancier breeds his animals. 
 
 At the Vivero hatchery, Mexico, the food consists largely of Gammarus, which 
 are there to be had only in a miry marsh. These impregnate the trout with a peculiar 
 muddy or marshy taste. To obviate this, trouble the shrimp food is suspended some 
 two mouths before the marketing of the fish, and nutmeg and ginger is added to the 
 other articles of food for the ])urpose of imparting an aroma or Havor to the flesh of 
 the trout. If the American palate objects to the combined flavor of nutmeg and trout 
 there is reasim to believe that the objectionable article might be replaced by some 
 other flavor more acceptable. It is the writer's opinion that such a condition as 
 pro])hesied by Mr. Green can not be induced by the use of a luainiiial diet solely; but 
 Sefior Ch4zari has demonstrated the possibility of flavoring the trout flesh by mixing 
 vegetable with animal matter. 
 
 Should it be- urged that trout raised on a mixed diet and intended for stocking- 
 streams would, when liberated, by reason of a perverted nature and taste, be untitted 
 for natural food, I may answer by referring to the difdcnlty of retaining fowls which 
 have been hatched from eggs taken from wild nests. In infancy they li«ve, thrive, and 
 fatten on the farm grains and kitchen scraps of bread and meat. One flue day they 
 leave for the woods or moors. Is it reasonable to suppose thtit they die for want of 
 thediet which served them so well in, infancy ? The process of reversion from domes- 
 tication to nature is always easier than the change from nature to domestication. 
 
 Little as is known of the correct rations and best food for flshes under domesti- 
 cation, there is less known (and fi-om the nature of things it will be more ditticult to 
 determine) of the very important iind high-power factors of range and space in deter- 
 mining the develo))ineut and rate of growth of fishes. It is well known to ev(U-y 
 cnlturist of experience that these are factors which should not be disregarded, and if 
 disregarded neither extra feeding nor additional water supply will comitensate lor 
 the lacking elements. At first, range and space may seem to involve natural food, 
 
FEEDING AND REARING PISHES. 303 
 
 and it must be admitted that to some extent this is so. But it is known that in pools 
 where the natural food is necessarily of a miuiuium (luantity (for if the pool is at all 
 well stocked it can only be that introduced in almost microscopic particles l)y the 
 inflowing water) a given number of trout would be outstripped in growth by half the 
 number on the same rations per thousand fish. This has been ascribed to exercise, 
 freedom of movement, a larger quantity of oxygen per fish, and various other causes. 
 
 Other things being equal, it is certain that the temperature of the water and tlie 
 proportion of the pond or pool subject to renewal each nuuute, or hour, will be found 
 controlling factors of no small consecpience. Of course, these elements may be, and 
 sometimes are, disregarded to the point of asphyxiation, but they are here mentioned 
 only as they influence development and growth. It seems certain that trout I'aised in 
 a high temperature grow more rapidly than those living in colder watervS, and it is 
 more than probable that where the current is very swift too much aliment is demanded 
 in the work of living. It is true that in the natural home of the trout many fine fish 
 are caught in the swiftest waters. Because primarily they are fine fish they are able 
 to stand the exertion and strain of living in this swift water; and so, being in position 
 to catch and enjoy the abundance of natural food which the current washes down from 
 the sources of the stream, they become the finer. Again I would warn the reader not 
 to confound domesticated trout in pools wiih wild trout in mountain streams. Mr. 
 Livingston Stone lays stress on cold, sunless water and close confinement as dwarfing 
 influences on trout, and urges the desirability of an abundance of warm water, range, 
 and plenty of space in growing large trout. 
 
 The following notes on the feeding of other species of fish at Neosho may be of 
 interest : 
 
 Black Bass. — The black bass {Mwropterus sulmoides) decline a vegetable diet in 
 any form, and can not be made to eat it. When mush is sometimes mixed with a 
 considerable (|uantity of liver they will take it in the mouth, but quickly spit it out. 
 The same results have attended frequent trials with crackers, bakers' bread, and dog 
 biscuit. They seem averse to vegetable diet, lu) matter how well disguised with a 
 mixture of meat. I have been unable to induce them to take artificial food except 
 liver, and it nuist be fresh and sweet. Of course, minnows or other fish have not been 
 tried, the effort being to overcome their natural inclination to eat fish. When the 
 liver, as it will occasionally in summer, becomes the least bit tainted the bass refuse 
 it. Sometimes they decline everything. This peculiarity of the bass is well known to 
 anglers. * In the Neosho ponds tlie l)ass rarely eat on nasty, raw days, but on pretty, 
 clear days they follow one around the pond, seeming to beg for food. The food of the 
 young bass was discussed in my paper. The Propagation of the Black Bass in Ponds, t 
 
 The Rock Bass (Ambloplitcs nqxsfris). — In the first eftbrts at Neosho to feed 
 these fish a small (piantity of liver was daily put in their pond, but it is doubtful if 
 they ever swallowed any of it. Sometimes they would pugnaciously dart out and 
 take a snudl piece in the mouth, to immediately spit it out. Formerly every few days 
 a small (juantity of liver was jiut in their pond to assist in breeding the insect life 
 which furnishes the largest and most acceptable part of their food. Por two years 
 past no artificial food has been expended on the rock bass. Their pond, of only 9,000 
 square feet water surface, is well planted with I'otamof/ctoit and Elodea, on which the 
 smaller Crustacea breed in such quantities as to support from 10,000 to 12,000 rock 
 
 * Hook of the Hlack Bass, James A. Heushall, p. 360. t U. S. V. (J. Bulletin, 1893, pp. 229-236. 
 
304 BULLETIN OF THE UNITED STATES FISH COMMISSION. 
 
 bass each year M'itliout the iutrodiictiou of any other food. Apart from any coiisid 
 eratiou of tbe value of these fish, they are the cheai)e.st boarders at the hatchery. 
 
 The Channel Catjinh eat the mush greedily. During the fall, winter, and early 
 spring they were dormant, and did not eome for their food. iSueh as was oftei'ed them 
 during this period sank to the bottom and remained unnoticed. At other times of 
 the year they rose to the surface and ate the mush ravenously, renuiiding one of pigs. 
 They are, as is well known among anglers, v ery fond of liver, it being a favorite bait 
 for them among the negro fishermen of the South. Very inrely we mixed a small 
 amount of liver with their mush*. 
 
 The Carp and its Allies. — The food for these fishes has received such excellent treat- 
 ment at the hands of Mr. Carl Nicklas that the reader is referred to the translation 
 of his Pond Culture, to be found in the Report of the V . S. Commissioner of Fish and 
 Fislieries for 1884. But I would state that in ponds not overstocked I have never 
 found it necessary to employ any animal diet for this class of fishes, though it is not 
 to be doubted that the lines of feeding laid down by Mr. Nicklas will produce the 
 most satisfactory results in securing the best marketable weight in the shortest time. 
 
 NATURAL FOOD. 
 
 The artificial ]iropagation of natural food thv fishes reared artiticially has received 
 the serious consideration of I^'uropean fish-culturists, and several of them claim to 
 have reached the solution of the problem and to be now rearing natural food in any 
 desired quantities at a not extravagant cost. Foremost among these was M. Lugrin, 
 of France, a description of whose se(;ret process may be found in the frenuently 
 quoted article published in the Bulletin of the U. S. Fish Commission for 1887. The 
 hope was held out last year, in the meeting of the American Fisheries Society, that 
 the French Government contemplated purchasing the secret of M. Lugrin and throwing 
 it open to the public use. 
 
 Mr. Thomas Andrews, of England, also has for some time past been engaged iu 
 rearing natural food, but, from my understanding of his letters, his process seems to 
 consist in allowing the natural food, principally (ianimurus and Limnaa, to multiply 
 naturally in reserve ponds and transfer tlie surplus to the ponds containing fish. 
 
 The method of Mr. C. G. Atkins, of tlie U. S. Fish Commission, can scarcely be 
 called, in the strict sense of the term, artificial propagation of natural food.t I take 
 it that maggots are in no sense natural food for Salmouida', and 1 think that the 
 method, because of its extreme malodorousness, will never be acceptable to the 
 attendant or the community in wliicli the work is conducted. 
 
 SeQor Chazari, of Mexico, uses natural footl iu considerable quantities, which, by 
 reason of peculiar environments and cheap labor, he is able to collect at the low cost 
 of 2i and 3 cents per pound. I understand that he neither breeds the insects after 
 the style of M. Lugrin nor uses reserve ponds alter that of Mr. Andrews, but relies on 
 iii'ighboriug swami)s as a base of supply. The local technical name of the Mexican 
 food is " mosquitte," and in answer to my inquiries Sefior Chazari wrote as follows: 
 
 It is a kiud (if uipiutii' insert, boing produceil iu laifji' <iuaiitities in our lakes iiertaiuiii;^ to tliis 
 iliatrict, especially iu that of Feveoeo, anil froiu which cousiderahle qnaiitities are collected every year, 
 mixed with larva' and other ariuatic iuseets. It is utilized exti^nsively as a food for singing birds. It 
 is a species ol'diriza, the Cor'nufviiiortita. It is very rich iu"azoi(l " principles (as are almost all insects), 
 aud even more thau others, and therefore is eousidered au excellent food for tish. I have preferred it, 
 
 ' U. S. Fish Commissiou Bulletin, 1883, p. 419; 1884, p. 321 ;' and 1886, p. 137. 
 t Bulletiu of the U. S. Fish Uommissiou, 1893, pp. 2^1 et seq. 
 
FEEDING AND REARING FISHES. 305 
 
 iu view of these highly estimable (jualities, ami because it can be given to trout without any mechan- 
 ical preparation, even to the smallest. Some 20,000 or yo, 000 pounds a year are collected. » • » its 
 only defect is that it keeps but for a short time. It rots, and is devoured rapidly by other insects 
 developed in it. 
 
 In the same letter it is .stated that rainbow trout at 1 year old, fed ou Goriza, 
 attain a weight of" KiO pounds per 1,000 fish. I know of no other place where 
 attention is given to the Coriza, except the Xeosho Station, where it is not used for 
 the trout but for the pond fishes, black bass, rock bass, etc. 
 
 Last year Mr. A. N. Cheney called attention to the methods of the Austrian, Carl 
 Elder von Scheidlin, who says: * "I, by foHowiug further on the lines of the French- 
 man, Lugrin, have .solved" the question of proper food, "and have tested the solution 
 as good, cheap, and practically feasible." Mr. von Scheidlin has proposed, through 
 Mr. Cheney, to make over his method of rearing natural food for use in the United 
 States, and correspondence is now going on to that end. 
 
 Up to the present time the only tangible efi'ort of a European in the direction of 
 cultivating natural food for fishes which the American fish-cuiturist can take hold of 
 has not been accomplished by a fish-culturist, but is the result of investigations and 
 experiments conducted by Dr. W. Koclis, of the University of Bonn, on the Artificial 
 Propagation of Minute Crustaceans. Tlie results of this work appeared in Biolog- 
 isclies Oentralblatt, October, 1892, and on account of its exceeding value a full trans- 
 lation is offered on pp. .300-308 of this paper. Occasion is taken to recommend for con- 
 sideration, i>articularly of the pond culturist, the suggestion of Dr. Kochs to construct 
 insect-breeding ditches along the banks of the ponds, from which the infusoria and 
 Crustacea may find their way into the ponds. Observation has fully convinced me of 
 the value of the hint given by Dr. Kochs of the fondness exhibited by (Tammarus for 
 dry brushwood, and I might state that the same seems true of all woods in which 
 decay has commenced; Corizu in particular seems to frequent half-rotted logs lying in 
 warm, shallow water, though I believe Gammarus prefers clean running streams. I 
 have found it most abundant in water of a temperature not unpleasant for drinking. 
 
 Translations of portions of reports by M. Chabot-Karlen on the fish-cultural 
 operations of MM. Durand, Binder, Despres, and other culturists of France are sub- 
 mitted on pp. 300-311. I would invite attention particularly to M. Durand's method 
 of pi'opagating the Ci/clopn, and I am prepared, from my own observations, to unquali- 
 fiedly indorse his remarks as to the value of Fotamogeton and Nasturtium as a shelter 
 for the smaller Crustacea. 
 
 As before intimated, litth^ or no systematic attention, except on an experimental 
 scale, has been given this subject by American fi.sh-culturists ; the only approach to 
 the European method of which I am aware being that at the i^rivate ponds of Mr. 
 Fairbank, of Illinois, and even there the effort is like that of Mr. Andrews. 
 
 One of the objections which has been raised to the employment of natural food 
 is the time and expense which would be involved in collecting enough for feeding a 
 large number of fish. To this I make answer: First, be certain how much food you 
 need to produce the best results. A comparison of the values of different foods as 
 determined by chemical analysis and as exhibited ou page 295 will show that from 7 to 
 10 pounds of the artificial food may well be replaced by 1 pound of natural food. I 
 say well replaced, because if 1 pound will do the work why burden the system with 
 the useless 9 pounds 1 
 
 " U. S. Fish Commission Bulletin, 1893, p. 278. 
 F. C. B. 1894—20 
 
30(j BULLKTIN OF THE UNITED STATES FISH COMMISSION. 
 
 EXPERIMENTS WITH ARTIFICIAL PROPAGATION OF MINUTE CRUSTACEANS.* 
 
 By Dr. W. Kochs, Univcrsily of Bo7in. 
 
 Within the last twenty years fisb-ciiltiirists have become more and more convinced that tlie 
 kuowledfie and dis-semination of minute crustaceans .and other h>\ver animals inhabitiuj; fresh water 
 are of the greatest benefit to fishing. The growth of the young brood and the faculty of the full- 
 grown fish to increase under favorable conditions are in the first instance regulated by the facility of 
 obtaining good food, and this regularly and abundantly. Emil Weeger delivered an interesting lecture 
 on this subject at the International Agricultural and Forestry Congress at Vienna in 1890, which 
 was later published with illustrations showing " strongly magnified representations of several species 
 of crustaceans frecjuently found in the waters of central Eurojie and insects belonging to tlie family 
 of gnats, May tlies, and daytlies, all serving as food for fishes." 
 
 At the close of this lecture Victor Burda, fish-culturist of Bielitz, spoke on the same subject 
 and added, relative to the propagation of fish in large ])onds, that these small infusoria were not only 
 of the greatest importance for salmon-breeding, as stated by Weeger, but also for carp-breeding ; it 
 was a subject which would demand the greatest attention among experts, because it was known ever 
 since the well-known exjiert. Director Lusta, had lifted the veil behind which the ijuestiou of the 
 nutrition of the carp liad been screened for so long a time, that the principal food of the carps, like 
 that of the salmon, not only in its earliest stage, but also later, consists of animal life, and he asks 
 why the artificial V)reeding methods of the water fauna, as suggested by Weeger, should not be 
 adopted. 
 
 Mr. Burda then continues and points out some measures by which the propagator might exert a 
 beneficial inlluence upon the growth of this minute water fauna. Starting from the idea, aiul this 
 idea is correct, that the minute crustaceans live on infusoria, and that these infusoria again thrive on 
 plants in the process of decomposition and on animal life, he endeavors to supply the j)onds with the 
 necessary and appropriate food. He says : 
 
 " The decomposed substance serving as food for tlie infusoria accumulates on the bottom of the 
 pond, and is .-dso mechiinically distributee! in the water, giving it a muddy appearance. The substance 
 distributed in the water partly originates on the bottom, partly enters the pond with the new influx, 
 in which case it comes from tlie soil, near by or far ofl', according to the condition of laud or water. 
 The more luxuriant and the more fertile the land the richer the ingredients waslied into the pond. It 
 18, therefore, of the greatest importance to have the greatest amount of tbis muddy influx led into 
 the pond after a heavy rainfall." 
 
 This IS doubtless correct, but it is also a fact that this ac(iuisitiou to the pond is gained at the 
 expense of tlie surrounding lands, because they are impoverished by the heavy rainfalls. Of course 
 considerable values in the shape of organic and inorganic substances wash from the fields into the 
 brook, from there flow into the rivers, and then into the ocean, and so would become lost if they 
 were not collected in the ponds and subsequently absorbed by the fishes. But a correct pond 
 propagation must not depend on circumstances; just as a certain quantity and quality of manure 
 must each year be supplied to the field to produce fair crops, sp the same action must be taken in 
 regard to the fisli ponds. Dr. Kochs tried for a year to catch the crustaceans described on Weeger's 
 j>lates and to breed them in glass vessels holding from 8 to 10 liters (1 liter is equal to 2.113 pints) 
 for tlie purpose of investigating their conditions of life. He found them only in puddles, which 
 received their fertilizing substance from the surrounding land or from animal cadavers. In one case, 
 in a puddle in a clay pit near Wintirschlick, he found that dung particles had l)eeii washed into the 
 puddle from an adjoining sloping orchard, where numerous dung heajis were found. The consequence 
 was a luxurious vegetation and numerous crustaceans in this puddle, while in many other adjacent 
 puddles liardly anything living could be detected. 
 
 It is not essential to catch a great number, because they increase wonderfully. To obtain those 
 species in a perfect condition, which collect between the water plants, he used a ]iear-shaped pipette 
 holding 1 liter, having a long and strong, but n.arrow, neck, and on the otlier end, in the pear, an 
 aperture 1 centimeter wide. When, closing the narrow neck and placing the pear end of the vessel in 
 the water, the stopper is suddenly removed, the water will rush into the vessel, carrying with it the 
 small infusoria. It is not possible to catch nearly as many with mull netting, besides the latter is 
 unserviceable lietween the water plants, and it is diflicult to separate the infusoria from it. 
 
 Dr. Koclis lias prepared since June, 1891, a inimlier of glass vessels as aquaria, in each of which he 
 placed all kinds of crustaceans. Some he kept at his private residence in the open air and during the 
 
 ' Translated by H. H. Gerdes from Biologisches Centralblatt, Band xii, pp. 599-606. 
 
FEEDING AND REARING FISHES. 307 
 
 winter in a warm room ; otUers he kept in the Pharmacological Institute in a room not heated, hut not 
 exposed to frost; others, again, since January, at the Physiological Lahoratory for Animals at the 
 Academy of Toppelsdorf, near Bonn, in a room exposed to all atmospheric changes. One set of the 
 aquaria was prepared as called for hy Weeger ; that is, 10 cubic centimeters of garden soil were 
 placed on the bottom and soaked with liquid manure; on this was placed mud from the puddles 
 containing crustaceans, and on this, again, dry leaves of hazelnut and willow trees. The aquarium was 
 then filled up with water. Some filiform algic, Wulffia, and other small water plants had entered into 
 the aquarium with the rand. In the course of two weeks there developed in all the aquaria minute 
 crustaceans (shell insects, Hea lobsters, water raultipedes, infusoria, green algfe), a felted mass of 
 filiform algiT>, and a thick cover of Ifolffia. The warmer the aquarium the quicker and better was the 
 development, but the plant life seemed to prosper better thau the aniuuil life. By catching these 
 small crustaceans in proper pipettes it was shown that the quantity in the aquarium was less thau in 
 running water. 
 
 Subsequent experiments proved that tlie majority of the Crustacea were very easily affected by 
 even the smallest quantity of ammonia, sulphureted hydrogen, or free acids, as also stated by Weeger. 
 It is clear that only the most fivorable conditions for the development of the Crustacea in the aquaria 
 prepared according to Weeger are mentioned. Tlien comes a period, which passes (|uickly, develop- 
 ing a good deal of tliis animal life. Dr. Kochs tried to accelerate the increase by tlirowiug in small 
 pieces of meat or dung, sometimes with more or less success, and to raise larger individuals, having 
 the most success with the water multipedes. 
 
 These experiments soon convinced him that water in which the Crustacea grow well and increase 
 was too nncleau for moat fishes; moreover, the Crustacea require warm and more or less stagnant 
 water, and can, therefore, only be raised in shallow puddles exposed to the snn and containing many 
 water plants, whereby it is clearly shown that the propagation of infusoria for fish food must be 
 entirely separated from the breeding of fishes. When attempting to breed both in the same vessel, 
 either the water fauna jirosper an<l in that case the fishes can not live, or vice versa. He ascertained, 
 also, through special exi)eriments, that the minute Crustacea could hardly live in water most favorable 
 for the growth of ndcroscopic plant life. 
 
 Mixing 0.1 liter of nitrate of ammonia, 0.1 liter of biphosphate of potash, and a minute (juantity 
 of iron with the strongly calciferous water from the city hydrant in Bonn, and adding a small 
 number of water plants, the water will soon turn strongly green and turbid at a temperature of 
 from 10- to 12^ C. (.50° to 54^ F.), and becomes slimy on account of the alga>. Daphnia and Cypria 
 will hardly grow therein. 
 
 His aim to first produce, in the proper manner, large (juautities of greenish water rich in plant 
 life for the sustenance of the Crustacea proved a failure. Still it is true that many Crustacea live 
 on microscopic plants, but the nio.st favorable conilition of life does not tally with that of the plants. 
 
 The Crustacea are only good in transparent anil clear water; all the fine aquaria tested for years 
 contained large water jilants, but also always clear water. 
 
 Later he exiierimented as follows: 
 
 To make the method to breed Crustacea artificially practicable and feasible the material needed 
 must be easily accessible and cheap. If the breeding is done in 8i)ecial receptacles (reservoirs) it must 
 be done in such a way that it will be easy to get the infusoria clean when fed to the fishes. The fol- 
 lowing experiment led him to a procedure which in his opinion will prove successful : Taking two glass 
 vessels each containing 10 litersof water (21.13 pints) and adding 100 grams (3.53 ounces avoirdupois) 
 of fresh cow manure without straw iu such a way that in one vessel this manure is evenly distributed, 
 while in the other these 100 grams of manure are placed in a glass cup and covered by wire netting, 
 it will soon be observed, especially where the temperature is warm, that a strong decomposition takes 
 place in the first-mentioned vessel, a thick scum of bacteria is formed, the liiiuid turns light-brown 
 and smells strongly of musk and ammonia. Cypria and Daphnia may live, and even increase, in this 
 bad-smelling liquid, if the temperature is not too high, and under the described conditions. On the 
 other hand, there is hardly any smell in the second vessel, where the manure is inclosed in the cup. 
 The gases forming in the manure raise the cup, bottom upward, to the surface of the water, which is 
 soon covered with a scum consisting of numerous bacteria and infusoria. The outer side of the wall 
 of this cup, and also the bottom of the large vessel, is soon covered with a white slime, also consisting 
 of bacteria and infusoria. After some time only organisms are developed containing chlorophyl 
 (green coloring matter of leaves or plants) in large quantities. Daphnia, Cypris, Cyclops, and many 
 other Crustacea grow finely in such a vessel. The wire netting which prevents the cow manure from 
 mixing with the water is thickly covered with minute Crustacea searching for food. As the water 
 
308 BULLETIN OF THE UNITED STATES FlSH COMMISSION. 
 
 remains nearly clear, it is somewhat easy to catch the animals, and one may so become conviuced of 
 the phenomenal increase. 
 
 Under the influence of water and warmth a vast development takes place of those numerous 
 microorganisms contained in the cow manure which absorb the undigested parts of the manure, and 
 which serve themselves as food for the Crustacea. The manure gradually disappeared during the 
 months of May, June, and July. When these Crustacea are fed to small carp or goldfishes a gradual 
 transformation of cow dung into fish is accomplished, almost without the help of plants. 
 
 The Gammartm pulex has lately frequently been found in large quantities between old bricks and 
 half-rotten brush wood in the Endenich Brook, near Bonn, without any cells containing chloropUyl 
 having been found in the water or mud. The water of the brook was muddy, because it contained the 
 waste and drainage of several adjoining villages. This relatively large crustacean grows splendidly 
 in an aquarium prepared with cow dung, as previously desoribeil, if a little dry brush wood is added. 
 
 Practically, it will be easy to produce this transformation of cow dung into fish, subject to local 
 conditions. The most advantageous way would seem to be to dig ditches along the banks of the pond 
 about 1 meter wide and 25 centimeters deep (about 40 inches by 10 inches) connected with the pond 
 by numerous narrow cuts. Perforated boxes or flower pots filled with cow dung are then placed in 
 these ditches and protected from the rays of the sun. When this shallow water is warmed by the sun 
 a great quantity of infusoria and Crustacea will develop, which by the rise and fall of the water in 
 the pond are sucked into it. If the banks of the pond are low, the fertilizing substance will settle 
 there, thus enlarging the area for the breeding of the Crustacea and forming a feeding-plaoe for the 
 young fishes. 
 
 All these infusoria are esjiecially sensitive to light. The ditches and banks must have old bricks, 
 brushwood, leaves, etc., for the protection of animal life. A luxuriant growth of water plants, 
 especially IVo}ffia, must be prevented, because it absorbs too much nourishment from the water; that 
 is, the nourishment is collected in the plant in such a shape that it is unserviceable for the purposes 
 of fish propagation. ' 
 
 These breeding ditches must, if possible, be dry in winter, so that the frost may easily penetrate. 
 In that case the winter eggs of the Crustacea, bedded in the mire, will develop better and more numer- 
 ously in the spring than when having overwintered in water. It would be very interesting, but very 
 difficult, to determine the causes of this peculiar process. Dr. Kochs exposed the mud of several 
 aquaria in an open box to the sun, to rain, and to frost by keeping it in the gutter of the roof of his 
 residence. By putting samples in glass vessels filled with boiled hydrant water and placing them in 
 a warm room, thei'o developed within three weeks Ci/pris, Daphnia, .and microscopic wheel aniuuilcnhi', 
 especially Hydalina aeiita and infusoria. It is certain that the eggs had several times been exposed 
 to — lO^C. iU"^ v.). At the end of May several samples of the same, nowair-dried mud, were put into 
 water previously boiled, and in two weeks nnmerous Crustacea had again developed. By drying a 
 large quantity of egg-containing mud in the fall, the proper food may easily be bred in tlie spring and 
 summer. 
 
 It must here be stated that the eggs will not stand a drying over sulphuric or anhydric phosphoric 
 acid. When that is done they all die, as has often been observed. This is mentioned because it is 
 frequently asserted that the eggs of the lower animals may live for one or more years in the thoroughly 
 dried mud puddles. Even mud, cleft and disrupted by the action of the sun, still contains several 
 parts of water. A total drying up of the eggs, therefore, does not take place in nature. 
 
 Dr. Kochs made special ex))eriments with the Helix pomaliti, and found that under the usual condi- 
 tions the moisture of the living animal does not dry up in a year, <!ven in a warm room ; moreover, as 
 soon as a dry crust has been formed around it, it loses the moisture only in artificially dried air, but 
 it dies before all the moisture is alisorbed. The poisonous substances forming at the bottom of the 
 ponds by a slow decomposition of organic substances at such times of the year when there is no frost 
 are destroyed by the plant life. These infusoria, and also the eggs of the lower animals, are frequently 
 threatened by an accumulation of those poisonous substances during .such times in winter when this 
 process does not take place. Half-decomposed organic substances are loosened and made spongy by 
 the frost, and later on easily crumble or dissolve. Only the drying and freezing of the mud, there- 
 fore, can be recommended. 
 
 * I think it pertinent at this point to remark that Dr. Kochs's warning against allowing a luxuriant 
 growth of water plants in the ponds has reference to his method of " transforming cow dung into tisli 
 without the help of plants." Ordinarily— that is to say, naturally — tlie ri8 or fertilizing strength of tlio 
 manure would go to making a luxuriant growth of ]>iant life, wliich in turn would be converted into 
 the low forms of animal life exhibited in the infusoria and Crustacea. 
 
FEEDING AND REARING FISHES. 309 
 
 REPORT BY M. CHABOT-KARLEN OX THE FISH-CULTURAL OPERATIONS OF M. DURAND, 
 AT THE SCHOOL OF AGRICULTURE AT BEAUNE.* 
 
 The author states that lish-cultiiral operations were commenced at the School of Agriculture 
 and Viticnltiire of Beauiie in 1886-87, near the Bouzaize, one of the affluents of the SaAne; that there 
 were at the time no trout in the vicinity or in the neighboring riverLS, and that it was necessary to 
 buy eggs. The first year 12,000 fry were obtained, which were divided into three lots. Two lots of 
 .S.OOO each were planted iu tlie ( )uclie and Muzin : the rest were liberated in the Bouzaize or held in 
 continenient near the sliorc and fed on Ci/cloim and afterwards on Gammariiti. The second year 17,000 
 fry were obtained; the two rivers above named received 0,000, the Vouge but 1,000; 500 were plaute<l 
 in the Love, and the rest put into tjie Bouzaize, a part at liberty aud a jiart in confinement. At the 
 present time 18,000 fry are ready to be distributed. In three seasons 17,000 fry have been turned out. 
 
 In the Ouche, iu which tlio trout were previously unknown, it is now possible to t;ike them 
 weighing 400 grams (about 14 ounces), those that were put in tirst being 23 months olil. M. Brossard, 
 director of bridges and roads at Bligny-sur-Ouche, s.ays that numbers of them of this weight can be 
 seen in the upper parts of the stream. As to those 1 year old, they have attained a weight of 100 grams 
 (.about 3i ounces). Moreover, natural reproduction will commence next season, and the conditions in 
 this river are so favorable that its stocking by this method is assured, as the lish will be iu condition 
 to spawn in December, 188i). In the Muzin the same results would have been obtained had it not been 
 for poaching. Nevertheless, iu spite nf this and of the devices of every kind that were employed by 
 the mills along the stream, the trout reappeared in the Muzin. 
 
 More or less siinihir results were obtained in the Bouzaize. Reared in captivity in receptacles 
 abunil.iutly provided with aquatic plants, I'otamofiefon aud cress, and fed with Cychips and aquatic 
 larv;v of every kind at first, and then with Gammanis, the trout gained iu a year an average of 60J 
 grains (about 2 ounces). At this age they were not able to cope with the large pike that infested 
 the mill course at the head of the river; tliis was emptied aud the larger ones taken out, only those 
 of the size of the youug trout being penuittcil to remain. Now, at the age of 23 months, a great 
 nnmberof the trout weigh more than 31)0 grams (about lOi ounces). Tlie following .are the weights 
 of some taken in the river: First, 30.5 grams; second, 360 grams ; third, 280 grams; average weight, 
 335 grams (about 11+ ounces). So that iu a year their weight iucreased from dOi to 335 grams, a gaiu 
 of 274i grams iu twelve months. Natural reproduction may be expected to commence in this river 
 from December, 188'J. 
 
 The report also contains observations on the Ci/clops (which are presented with a view to furnish 
 ing the basis of a method for the rearing of these), the Daphnia, aud the Ci/pris, with some remarks 
 on the monstrosities found with th'i eggs of the trout and a statement of prices obtained for trout. 
 
 The Ci/cIops possesses an extiaorilinary fecundity, and reproduces at a temperature of from S'^ to 
 10° C. (46-^ to 50^ F. about). In winter they seek the bottom and hibernate in some sort, but on 
 capturing them and placing them iuahighir temperature their generative organs will be seen to 
 revive. Thirty -five degrees C. (95° F.), however, according to our experience, is the highest they 
 can resist. The best for batching is between 20° and 2.5" C^ (68° and 77° F.). At this temperature there 
 forms on each female every two days two egg-bearing sacs, or external uteri, wherein the eggs are 
 hatched. At the end of two d:iys tliese organs become detached and fall to the bottom. The number 
 of eggs coutaiued in eacli may be from 16 to 32, but generallj' the number of young obtained is some- 
 what less. However, the eggs hatch immediately, aud the young Cyclops which issue forth are almost 
 globular, haviug but lour feet and no tail. At the end of fifteen days they undergo a luidting, the 
 tail appears and otlier feet form, and fifteen days after — that is, a month in all, the Cyclops are mature 
 and ready to reproduce. 
 
 With such feeuudity, it can be readily understood how numerous they become. Carlxmate of 
 lime is necessary in th ■ formation of their shell. From the fact that they are fouuil iu abunilance iu 
 water infused with vegetable matter in decomposition, the water, nevertheless, not contracting the 
 least odor, it is sup])OSed that they live on infusoria, aud that, therefore, the means by whi<!h the fish- 
 cultnrist may have them at his disposal is to multiply in his rearing ponds aquatic i)lant8. (Potamo- 
 
 ' The report was published by the National Society of Agriculture of France, .Tune 19, 1889. The 
 papers in this Appendix were translated by Mr. F. P. Feunell, of the U. S. Fish L'ommission; none of 
 thein have lueu translated in full, only such portions being presented as apply to the feeding and 
 rate of growth of the fishes. 
 
310 BULLETIN OF THE UNITED STATES FISH COMMISSION. 
 
 geton crispus gives the l)e9t results.) In this way the Cyclops will live and reproduce with the j-oung 
 fish. By digging in .1 neighboring field one or more holes into which is introduced a small stream of 
 water and pl.'icing thereiu the Poiamogetons and fountain cress {Nastiirtiiitn offirinnlis'!) (this Inst 
 agrees with the Uammaras) a temperature will be obtained .at which the Ci/chps can propagate in 
 great numbers; .and there will be at h.aud in abundance the best food that can bo given to the young 
 fish. The fish-culturist who possesses cliiyey land can undertake this without expense. In basins so 
 prep.arod it will not bo long before conferva' and vaucherias will be seen to form, which, .after a while, 
 becoming decomposed, will take on a brown tint, and in the midst of which the little creatures will be 
 very abund.ant. 
 
 For collecting the Cyclops a simple net is used, simil.ar to that employed by entomologists. This 
 lets the water pass and retains a multitude of .auim.alcules, not only Cyclops, but the larvai of gnats, 
 Hydrachnas, etc., of which the fry are very fond. 
 
 The rearing of Daphn'ui pulex and Cypris fiisca was also tried. The Cyjnis, however, were found 
 to prey upon the young fish. Having been put in with the embryos of the carp, they were often 
 discovered to the number of two or three fixed upon the back of an alevin devouring it, notwith- 
 standing the efforts of the poor animal to shake itself free. It was, therefore, necess.ary to abandon 
 their use, and with regret, because their fecundity is certainly much greater than that of the Cyclops, 
 and they mature much more quickly. It is believed that this fact is aljsoliitely new in the history of 
 applied fish-culture. 
 
 Finally, attention is called to the great number of monstrosities foiuid .among eggs taken from the 
 trout at Vougeot, at the establishment of M. Peloux. These breeders were reared by M. I'elonx .and 
 came from the same parents, and it is asked whether these deformities may not be attributed to 
 consanguinity. 
 
 REPORT BY M. (;H.\nOT-I{.\RLEN ON THE FISH-CULTUR.4L OPERATIONS OF M. BINDER, 
 PROFESSOR AT THE SCHOOL OF AGRICULTURE OF SAINT-REMY (HAUTE-SAONE).* 
 
 In this paper it is stated that during the three years that fish-cultural oi>erations were conducted 
 at this school 100,000 trout were jilanted in the Lanteine and Moselotte; and that such good results 
 were ol)taiMed in the Lanterne that the young fish could be seen therein as numerous as minnows; 
 that those 14 months old weighed 8 to 16 gr-ams (0.28 onuee to 0.56 ounce) with a length nf 7 tn 12 
 centimeters (2.75 inches to 4.72 inches). 
 
 REPORT BY M. CHABOT-KARLEN ON THE NOTES OF M. DESPRfiS, PROPRIETOR OF THE 
 FISH-CULTURAL ESTABLISHMENT OF NANTEUIL-EN-VALLEE (CHARENTE).f 
 
 This pa]ier has reference to the notes of M. Desjircs on rearing salmonid.T by .artificial food. He 
 says that the development of the embryo especially .attracted his attention; that it w.as between the 
 third and fourth day before the absorption of the s.ae that the alevin would become hungry and com- 
 mence to eat, not seeking its food, but lying in wait for it; that six or .seven days .alter it would quit 
 its hiding-place .and .attack its prey, snapping at it while in movement in the water. He then enters 
 into a description of the means to be employed for the protection and feeding of the young, and he 
 seems to have succeeded in his experiments if, .as he says, ho is able to guarantee the rearing of 00 jier 
 cent. At Howietoun it is on the weight (one-fiftieth of the living weight) that is determined the food 
 to be given, a method which .appears more scientific and at the same time more practical than that of 
 feeding them without regiird to .ago or development. The choice of food largely depends upon environ- 
 meut. At Howietoun moUusks .are used to ,a*gre.at extent, while .at Niinteuil brains, blood, .and Limax 
 satisfactorily replace these shore animals, of which the alevins are very fond. 
 
 " Published by the Nation.al i^ociety of Agriculture of France, .Tuue SO, 1886. 
 t Presented to the National Society of Agriculture of France, June 30, 1886. 
 
FEEDING AND REARING FISHES. 311 
 
 REPORT RY M CHABOT-KARLEN ()\ THE VIEWS OF M. EMILE RIVOIRON ON THE 
 REARING OF TROUT BY NATURAL FOOD.* 
 
 M. Rivoiron says that the youug trout do not takes food except when it is moving in the water; 
 that they do not go to the bottom. Unle.ss great care is taken, which is not always possible, failure 
 is certain in the use of artificial food on .account of decomposition. Of the natural food M. Rivoiron 
 prefers the Daphnias. To rear tliese he says: Dig near the side of the stream two, four, or six basins, 
 from 10 to 12 meters (about 32 feet and 9 inches to 39 feet and 5 inches) long, by 2 meters (6i feet) 
 wide, and IJ meters (about .5 feet) deep, according to the number of Daphnias to be produced. Clayey 
 soil is preferable, .as the water with which the basins are tilled will not quickly evaporate. In these 
 there should be pl.aeed during March, at the north end, because the basins should be dug as ne.ar as 
 possible from north to south, one cubic meter (about IJ cubic yards) of fresli dung (cow dung and 
 horse dung mixed). 
 
 Every day the water should lie stirred until it takes on a light-brown color, without, however, 
 becoming tainted. On this point depends somewhat the success of the micniscopic beings that 
 during the first days of April should l)e deposited there. At a temjierature of 25^ C. (77- F. ) each of 
 these will give birth every five days to eight i>thers, which in a few weeks will amount to millions. 
 They reproduce even at a temperature of 32^ ('. (al)out 90' F.), and sustain a temperature of — 6° C. 
 (about 21"-^ F.). The least shock will kill them en masse. Under no circumstances should the water 
 be disturbed, and they should be gathered with the utirio.st care. Thi.s gathering (a sort of skimming) 
 can be commenced at the end of April and continued until the end of September. It can be done by 
 means of .a strainer, which should be brought gently to the surface. Before being given to the 
 alevins the Daphnias should be placed in fresh water, in order to rid them of the odor with which 
 they may be impregnated; otherwise they will kill the young fi.sh. It is supposed that the ammonica 
 in the rearing basin is the cause. A basin should never be fished to the bottom, and eight or ten days 
 should elapse, according as the temperature will have more or less favored the multiplication of the 
 Crustacea, before reconnuencing the operation. When giving them to the alevins the same precau- 
 tions should be taken with the Daphnias as when collecting them, and it is essential that they should 
 be deposited in the water vei"y slowly. A basin of the above dimensions will cost .35 francs, and will 
 furni.sh, from April to September, from 170 to 180 kilograms (371 to 396 pounds, avoirdupois) of 
 Daphnias. An .alevin so fed will weigh at six months 1? grams (0.21 ounce), with a length of centi- 
 meters (about 2'i inches). 
 
 * Made to the National Society of Agriculture of France, July 1, 1885. 
 
312 
 
 BULLETIX OF THE UKITED STATES FISH COMMISSION. 
 
 BIBLIOGRAPHY. 
 
 [The follo\Ying table contains a partial list of reforeuces to articles on the food of fishes, artificial 
 anil natural, under domestication and in natnre. The ahljreviations R and B are for the Reports and 
 Bulletins of the United States Fish Commission, T for the Transactions of the American Fisheries 
 Society, and ^ has reference to miscellaneous publications, a list of which is given at the close of this 
 appendix.] 
 
 Artificial feeding of carp 
 
 cultivation of trout m Japan 
 
 Black bass, food of 
 
 Do 
 
 Do 
 
 Carp and trout, cost of food 
 
 artificial feeding of 
 
 feeding the 
 
 Carp, food of 
 
 Do 
 
 Do 
 
 Do 
 
 Carp, food of, pond culture 
 
 Do 
 
 Carp, food and liabits 
 
 Do 
 
 Carp and other fish, how to raise 
 
 food, in California 
 
 tront and, manufactured food... 
 
 Nicklas's food discussed 
 
 Catfish and tront, feeding 
 
 fed on corn meal 
 
 Carl Xicklas 
 
 Sekizawa .4^kekio.. 
 .' Dr. .1. A. Henshall. 
 . Discussion 
 
 food of . 
 
 China, food for fry in 
 
 Codfish eat herring spawn 
 
 food o f 
 
 Color affected by food 
 
 Cost of fish food 
 
 food for carp and trout 
 
 Crawfish, food of 
 
 Do 
 
 Do 
 
 Crustaceans, cultivation of, for fish food. 
 
 Device for feeding fry 
 
 Embryo fishes, food of 
 
 Expenses of food of fresh-water fish 
 
 Fish fed by lake dwellers 
 
 food and feeding 
 
 J'ish, food of 
 
 Do 
 
 Do 
 
 Fishes in confinement, food of 
 
 food of 
 
 Food fish and fish food 
 
 Food habits, teeth as a guide to 
 
 Fresh-water fish, expense of 
 
 food of 
 
 Fry, device for feeding 
 
 fJadus morrhna 
 
 German fish, food and digestion 
 
 Goldfish, food of 
 
 Do 
 
 Gourami, food of 
 
 Grayling, food of 
 
 Herring, artificial feeding 
 
 A, .1. Malmgren 
 
 Carl Nicklas 
 
 Dr. R. Hessel 
 
 L. B. Logan 
 
 Dr. R. Hessel 
 
 Carl Nicklas 
 
 C. W. Smiley 
 
 Adoljdi Gasch 
 
 Carl Nicklas 
 
 Hugh D. McGovern 
 
 ...do 
 
 Max von deni Borne . . . 
 
 Robert A. Poppe 
 
 Dr. C. O. Harz 
 
 Baron von K 
 
 A. I'. Gardner 
 
 Naman May 
 
 R. O. Sweeney 
 
 B. F. Jones 
 
 H. Kopsch 
 
 I'rof G. O. Sars 
 
 M. Friele 
 
 I. Bean 
 
 Goldsmith 
 
 JIalmgren 
 
 (Jetmaii Fishery Asso'n . 
 
 N. |\'ers;eland 
 
 ubelius 
 
 iVergeland 
 
 O. Chambers 
 
 J. A. Ryder 
 
 .1. J. Manley 
 
 Ciirll'evrer 
 
 J. P. .l."Koltz 
 
 Philo Dunning 
 
 Eugene Blackford 
 
 V. Hensen | 
 
 FredMather j 
 
 A.N. Chenev \ 
 
 do ' 
 
 Dr. J. A. Hensh.all ... 
 
 J.J. Manley 
 
 Sidney I. Smith 
 
 W. O. Chambers 
 
 Karl Dambeck 
 
 Dr. P. Pancritius 
 
 Deutsch. F. Zeit 
 
 Hugo Mulertt 
 
 Theodore (iill 
 
 Prof. J. W. Milner... 
 H. Widegren 
 
 R 
 
 1882 
 
 R 
 
 1879 
 
 * 1 
 
 
 T 
 
 
 
 T 
 
 XII 
 
 B 
 
 1883 
 
 R 
 
 1882 
 
 R 
 
 1875-76 
 
 ^9. 
 
 
 R 
 
 187.5-76 
 
 B 
 
 1883 
 
 B 
 
 1883 
 
 R 
 
 1883 
 
 R 
 
 1884 
 
 T 
 
 X 
 
 T 
 
 XI 
 
 R 
 
 1883 
 
 R 
 
 1878 
 
 B 
 
 1884 
 
 B 
 
 1885 
 
 B 
 
 1883 
 
 B 
 
 1886 
 
 T 
 
 XVII 
 
 B 
 
 1884 
 
 R 
 
 1873-75 
 
 R 
 
 1876-77 
 
 R 
 
 1876-77 
 
 T 
 
 XVIII 
 
 R 
 
 1872-73 
 
 B 
 
 1883 
 
 R 
 
 1876-77 
 
 R 
 
 1878 
 
 R 
 
 1879 
 
 R 
 
 1878 
 
 T 
 
 XVII 
 
 B 
 
 1882 
 
 B 
 
 1884 
 
 R 
 
 1873-75 
 
 R 
 
 1880 
 
 T 
 
 XV 
 
 T 
 
 XII 
 
 R 
 
 1879 i 
 
 T 
 
 VI 1 
 
 T 
 
 XXI 
 
 T 
 
 XII 
 
 T 
 
 XX 
 
 B 
 
 1884 
 
 R 
 
 1872-73 
 
 T 
 
 . XVII 
 
 R 
 
 1876-77 
 
 B 
 
 1886 
 
 R 
 
 1878 
 
 «3 
 R 
 
 
 1872^73 
 
 R 
 
 1872-73 
 
 R 
 
 1878 
 
 1009-1031 
 
 646 
 
 164 et seq. 
 
 8 
 
 32 
 
 378 
 
 1009-1031 
 
 895 
 
 72 et seq. 
 
 869 
 
 403 
 
 245 
 
 114.3-1150 
 
 565-587 
 
 11-16 
 
 5-7 
 
 1133-1142 
 
 665 
 
 449 et seq. 
 
 290, 291 
 
 418,419 
 
 137 
 
 67 
 
 321 
 
 546 
 
 639 
 
 710 
 
 20 
 
 771, 772 
 
 378 
 
 782 
 
 584 
 
 767 et .seq. 
 
 555-573 
 
 2,5, 26 
 
 179-205 
 
 73 
 
 583 
 
 509-514 
 
 79-83 
 
 5-« 
 
 547 
 
 67 et sei|. 
 
 22 et seq. 
 
 27-32 
 
 24 et sei] . 
 
 73 
 
 708-709 
 
 25-26 
 
 533 
 
 145 et se(|. 
 
 679 
 
 67 et seq. 
 
 715 
 
 731 
 
 127 
 
FEEDING AND REARING FISHES. 
 Bibliography — Continued. 
 
 313 
 
 Subject. 
 
 Author. 
 
 Axel Ljungman 
 
 V. Hensen 
 
 A. V. Ljungman 
 
 Hjalmar Widegren . . . 
 
 Prof. G. O. Sars 
 
 A. V. Ljungman 
 
 Prof. G. O. Bars 
 
 ...do 
 
 M. McDonald 
 
 R. Rathbun 
 
 G. Urowu Goode 
 
 R. Edward Earll 
 
 P. 15. P. Hverson 
 
 Dr. C. O. Harz 
 
 Carl Nicklas 
 
 Prof. K. Jlobins 
 
 R. Ratlibuu 
 
 Prof S. A. Forbes 
 
 N. Wergeland 
 
 ....do 
 
 C. Raveret-Wattel 
 
 E. O'Brien 
 
 Muutadas 
 
 Herring, food of 
 
 Do 
 
 Do 
 
 Do 
 
 Herring food 
 
 Do 
 
 Herriug, red, food of 
 
 Herring spawn eaten by cod 
 
 Lobsters, food of young 
 
 Mackerel, menhailen and, food of ,. 
 
 food of 
 
 Spanish, food of 
 
 Mammoth Spring, Ark., food at 
 
 Manufactured food for trout and carp 
 
 Do 
 
 Mariuc animals, food of 
 
 Menhaden and maekerel. food of 
 
 Mississippi Valley, I'ood of fishes of 
 
 Natural food, cultivatiim of 
 
 cultivation of cru.st,aeeaus 
 
 piscicultural establishment at 
 Greniaz (.\in), France. 
 
 Natural food, cultivation of 
 
 report on juscicnltural estab- 
 lishment of Piedra, Aragon, 
 .Spain, 
 self-reproducing food for tisli. 
 
 Oysters, food of fry and spat 
 
 Perch, diseased and healthy 
 
 Pike, food of ' 
 
 Piscicultural establishment at Gnunaz ' -\in), 
 Fr.ance. 
 
 Plankton estimates, .some 
 
 studies 
 
 Pollack, food of 
 
 Propag.atiou of food for tisi; 
 
 Protozoa and protophytes 
 
 Protozoa ami protophytes (2d edition) 
 
 Red herring, food of 
 
 Report on ])iscieultnral establishment of Pie- 
 dra, Aragon, .Spain. j 
 
 Salmon, Atlantic, food of ! Sidney I. Smith . . 
 
 Sacramento, food of Livingston Stone 
 
 Do '....do 
 
 Salmonida', in ponds, best food fir 
 
 Salniouoids, raising in inclosed watens .. 
 
 .Salmon, trout, and shad, food of 
 
 .Sea-tishes, food of 
 
 Self-re|)roducing food for fish 
 
 Shad, food of 
 
 Do 
 
 Do 
 
 Shad, food of young 
 
 salmon, trout and. food of 
 
 Spanish mackerel, food of 
 
 Sturgeon, food of 
 
 Swordft.^h, food of 
 
 Do 
 
 Teeth, .a guide to food habits 
 
 Trout and carp, manufactured fooil for . 
 Do 
 
 Frank H. Mason... 
 
 .lobu A. Ryder 
 
 Prof. S. X. Forbes .. 
 Dr. C.C.Abbott ... 
 C. Raveret-Wattel . 
 
 •J. E.Reigh.ard... 
 Ernst Ilaeckel .. 
 Prof (J. O. Sars .. 
 
 M.E. O'Brien 
 
 Prof J.A.Ryder. 
 
 ....do 
 
 Prof G. O. Sars .. 
 F. Muntadas 
 
 German Fish Ass'n 
 Director Haack ... 
 
 D. B.arfurth 
 
 S. F. Baird 
 
 Frank H. Mason. .. 
 
 M.McDonaM 
 
 Dr. H. C. Yarrow.. 
 
 S. F. Baird 
 
 •lames W. Milner :. 
 
 I). Barfurth 
 
 R. Edward Earll .. 
 .lames W. Milner .. 
 
 G. Brown Goode 
 
 A. Howard Clark.. 
 Dr. .1. A. Henshall. 
 
 Carl Nicklas 
 
 Dr. C. O. Harz 
 
 Publi- 
 cation. 
 
 R 
 R 
 R 
 R 
 R 
 R 
 R 
 R 
 R 
 R 
 R 
 R 
 T 
 B 
 B 
 R 
 R 
 T 
 R 
 R 
 B 
 
 T 
 B 
 
 B 
 R 
 B 
 R 
 B 
 
 T 
 R 
 R 
 T 
 B 
 R 
 R 
 B 
 
 R 
 R 
 R 
 R 
 R 
 R 
 R 
 B 
 T 
 R 
 R 
 R 
 R 
 R 
 R 
 R 
 R 
 T 
 B 
 B 
 
 Vol. 
 
 1879 
 1879 
 
 1873-75 
 
 1873-75 
 
 1876-77 
 
 1878 
 
 1876-77 
 
 1876-77 
 
 1889-91 
 
 1881 
 
 1881 
 
 1880 
 
 XIX 
 1884 
 1884 
 1879 
 1881 
 
 XVII 
 1S78 
 1878 
 1887 
 
 XVII 
 1887. 
 
 1887 
 
 1885 
 
 1888 
 
 1875-76 
 
 1887 
 
 XXII 
 
 18H9-91 
 
 1876-77 
 
 XVII 
 
 1881 
 
 1881 
 
 1876-77 
 
 1887 
 
 1872-73 
 1872-73 
 1875-76 
 1876-77 
 1879 
 1873-75 
 1886 
 1887 
 XII 
 1872-73 
 1872-73 
 1873-75 
 1873-75 
 1880 
 ' 1872-73 
 1880 
 1881 
 XX 
 1884 
 1884 
 
 505,506 
 
 538 
 
 148 
 
 186 
 
 609 et seq. 
 
 181, 197, 21fi 
 
 691 
 
 639 
 
 164 
 
 41 
 
 105-111 
 
 403 
 
 46 et seq. 
 
 449 et seq. 
 
 453 et seq. 
 
 485-489 
 
 41 
 
 37-67 
 
 575 et sei]. 
 
 555-573 
 
 207 et seq. 
 
 29-33 
 211 et seq. 
 
 203 et seq. 
 
 387-388 
 
 485 
 
 845 
 
 207 et seq. 
 
 112 et seq. 
 
 56.5-641 
 
 592 
 
 29-33 
 
 236 et sf.n. 
 
 755-770 
 
 691 
 
 211 et seq. 
 
 371 
 
 190 
 
 808 
 
 779 et seq. 
 
 67.5-685 
 
 735-759 
 
 38-72 
 
 203 et se<i. 
 
 33 
 
 454-5 
 
 LVII 
 
 367 
 
 735-759 
 
 403 
 
 73 
 
 329 
 
 234 
 
 24 et ,seq. 
 
 453 et seq. 
 
 449 et seq. 
 
002 860 305 8 
 
 314 
 
 BULLETIN OF THE UNITED STATES FISH COMMISSION. 
 BiBLioonAriiY — Conthmcd. 
 
 Subject. 
 
 Trout, I'atlish niid. iVcdini; 
 
 nrtitifi;il rulturo in Japan. 
 
 oarp and, cost of food 
 
 feeding in confinement 
 
 po 
 
 feeding in ponds 
 
 Trout, food of 
 
 Do 
 
 Do 
 
 Do , 
 
 Do 
 
 Do 
 
 Do 
 
 Do 
 
 Do 
 
 Do 
 
 Do 
 
 Trout food, cost of 
 
 Trout, rainbow, food at Baird 
 
 salmon, and sliad, food 
 
 Transportation, feeding during.. 
 
 What does a tisli cost ^ 
 
 White(i,>b, adnlts, food of 
 
 food of 
 
 its earliest food 
 
 young, feeding 
 
 Whitelish, young, food of 
 
 Do -..■ 
 
 Do 
 
 Winter, food of lisli in 
 
 Utilizing water by Hsli-eulture .. 
 
 Yellowstone I'ark, food in 
 
 Young lisUes, food of 
 
 Author. 
 
 ] Publi- 
 cation. 
 
 Vol. 
 
 A. P. Gardner . ... 
 Sekizawa .Vkekio 
 A. J. Malmitren.. 
 
 N. Wergeland 
 
 Dr. Brumme 
 
 Roosevelt & Green . 
 
 Fred Mather 
 
 Carl Peyrer 
 
 Seth Green 
 
 F. N. Clark 
 
 Sir James Maitland. 
 
 AVni. F. Page 
 
 P. B. P. Hyerson .... 
 Livingston Stone... 
 Tliad<leuK Xorris. . . . 
 
 Dr. J. H. Slack 
 
 (iencral discussiim. . 
 
 Livingston Stone 
 
 D. Barfnrth 
 
 Livingston Stone . . . 
 Christian Wagner . . 
 
 .James W. Milner 
 
 Frank N.Clark 
 
 Prof. S. A. Forbes . . . 
 .lames W. Milner . . . 
 
 Frank N. Clark 
 
 Prof. S. A. Forbes . . . 
 W. O. Chambers . . . . 
 Dr. C. C. Abbott .... 
 
 Prof. E. Benecke. 
 
 R. Ratbbun 
 
 Prof. S. A. Forbes . . . 
 
 B 
 K 
 1! 
 T 
 R 
 1', 
 
 T 
 
 R 
 
 V^5 
 
 T 
 
 ^fi 
 
 T 
 
 T 
 
 \W 
 
 §8 
 
 ^\9 
 
 T 
 
 R 
 
 R 
 
 R 
 
 R 
 
 R 
 
 T 
 
 R 
 
 R 
 
 R 
 
 B 
 
 B 
 
 R 
 
 R 
 
 R 
 
 no 
 
 1883 
 1879 
 1883 
 VIII 
 1878 
 1884 
 
 XXI 
 
 1873-75 
 
 XXI 
 
 XXII 
 XIX 
 
 Page. 
 
 XX 
 
 1880 
 
 1873-75 
 
 1873-75 
 
 1878 
 
 1872-73 
 
 XVII 
 
 1881 
 
 1872-73 
 
 1880 
 
 1881 
 
 1887 
 
 1875-76 
 
 1883 
 
 1889-91 
 
 418-419 
 
 64fi 
 
 378 
 
 4-6 
 
 5.54 
 
 3.30-331 
 
 79-84. 130 
 
 87-93 
 
 .591 
 
 37 et seq. 
 
 78 
 
 01-264 
 
 71 et seq. 
 
 46 et se(|. 
 
 228 et seci. 
 
 73-68,231 
 
 123 et seq. 
 
 10 et seq. 
 
 618-619 
 
 735-759 
 
 394 
 
 605 et seq. 
 
 44 
 
 67 
 
 771-782 
 
 32, 57 
 
 586 
 
 19 et seq. 
 
 18 
 
 842 
 
 1101-1131 
 
 138 
 
 10-19 
 
 The miscellaneous publications referred to in the preceding list are as follows: 
 
 § 1. Book of the Black Bass, Dr. J. A. Hensliall. 1881. Robert Clark & Co., Cincinnati. 
 
 ^2. Practic.'il Ciirp Culture, L. B. Logan. 1S88. Youngstown, Ohio. 
 
 \ 3. The Goldlish and Its Culture, Hugo Mulertt. 188:i. McDonal<l & Eick, Cincinnati, Ohio. 
 
 ^4. Fish Hatching and Fish Catching, Seth Green and R. B. Roosevelt. 1879. Union Advertiser 
 Com])any, Rochester, N. Y'. 
 
 § 5. Trout Culture, Seth Green. 1870. Curtis, Moray A: Co.. Rochester, N. Y. 
 
 ^6. History of Howietoun, Sir J. Ramsay (iilison Maitland. 1887. Published l>y .1. R. Guy, secre- 
 tary Howictouu Fishery. Edinliurgh University Press, T. and A. Constable, printers to 
 Her Majesty. 
 
 ^7. Domesticated Trout, Livingston Stone. 1872. Fourth editiim. 1891. Cold Spring Trout Pouds, 
 C'harlestown, N. H. 
 
 ^ 8. American Fish Culture, Thaddeus Xorris. 1868. Porter & Coatcs, Philadelphia. Sampson 
 Low, Son & Co., London. 
 
 ^9. Practical Trout C'ulture, .1. H. Slack. 1872 American News Cimijiany, 39 and 41 Chambers 
 street, N'CW Aork. 
 ^ 10. Proceedings of the Central Fish-Cultural Society. 1880. 
 
SH 151 
 .P13 
 Copy 1 
 
LltSKHKY Ut- LUNUKtbb 
 
 002 860 305 8