The daily morning journal and courier., 1907-06-19
PROPER FOOD FOR FISHES.
Uncle sam Proposes to Find Out What
 They Thrive Best Upon.

They InrtYe Best UpOns
 It is proposed by the bureau of fish cries to take up practically neglected subject-the proper dietary of fishes. Chancey Judy, who is one of those dep uted by the bureau to inquire into the subject, said of the importance of the investigation:
 Although agrlculturists have lock- ed assiduously after the improvement of their stock by proper feeding, com paratively little attention has been giv- en to the food of our useful aquatic animals. The bureau now recognizes that the entire question of the relation of quantity and quality of food to the rate of growth and physical well being of fishes needs much more thorough in- vestigation than 1t has yet received.
 This neglect is certainly not due to the slight economic importance of the subject. It has been estimated that Q body of water of average fertility will produce five times as much as an equal area of average land.
 Attention has been called to the fact that small fish pond, 60 by 120 feet, In Indiana, produced 1000 pounds of black bass and 25O pounds of yellow perch in fifteen months without being supplied with artificial food. At the price of eight cents pound. 1t was estimated that if the natural waters of Indiana had been relatively only about tenth as productive as this particular pond the fish products would have been almost equal in value to the corn crop Of the State in 1S96. tho year of this experiment, and little more than twice the value of the wheat crop.
 "Yet in spite of the great possibili- ties of lakes and streams from an eco- homie standpoint, most of them receive little or no attention except when legls- lators wrestle with the problem of de- vising laws for the protection of fish and aquatic birds. There is little doubt that if more attention were given to Investigations relative to increasing tho producing efficiency of lakes and streams many of the protective laws now on our statute books would be- como superfiuous.
 Hike other living organisms, fishes ar, affected by both the quantity and the quality of the food available to them. The quantity of suitable fish food found in a stream or lake determines not only the number of fish that may be supported but also the physical con- dltion of those that do survive.
 Fish epicures have consistently maintained that the flavor of a poorly or improperly fed fish is much inferior to that of one which has had an abun- dant supply of the right kind of food Baird cites an experiment in which young trout were placed in three sep arate tanks and were fed on different kinds of food. The trout in one tank were supplied with worms, those in another with live minnows, while those in the third were fed upon waterflies.
 "The trout which subssted upon worms grew slowly and had lean ap- pearance, those which were supplied with live minnows became much Iarg- CT. while those which had flies alone given them attained in a short time prodigious dimensions, weighing twice as much as both the others together. It is, of course, true that there Is a very marked difference in the rate of growth of trout even under apparently l the same food conditions.
 Trout culturists, for instance, find 1t necessary to sort the young trout of a pond at regular intervals after they are a few months old, and separate the larger prococious individuals from the | smaller, weaker ones, in order to keep the former from preyng upon the lat ter. But in spite of this apparently contradictory evidence there Is little doubt that the great difference in the results obtained in the experiment have cited was due in some measure al least to the different kinds of food sup piled
 "As long ago as 1852 Walton appre- ciated the importance of the quality of the feeding ground, for he says: And certainly, as some pastures breed larg- CT sheep, so do some rivers, by reason of the ground over which they flow, breed larger trouts.' Francis QS5S) makes the assertion that trout in one stream will be much larger firmer, redder and better shaped than in oth- CTS This may, in measure, be owing to the greater abundance of food, but I have every reason to believe that it proceeds quite as much from the kind l of food that they are enabled to obtain.
 Thus 1t Is evident that knowledge | of both the quantity and kinds of food found in a stream or lake Is of very great importance when it comes to the question of trout culture. This, doubt 1 less. Is true also of the culture of all other fishes, and this knowledge, it is felt assured, would prove very valuable | in the introduction of species of fish | into new waters
 If we know the kind of food on which the fish thrlves best and if We also know the quantity and kinds of fcod available in the water to be stock | ed then we can attack the problem of | stocking the water in such way as | greatly to increase the chances of sue cess. Until such knowledge is acquired we must continue to experiment more l oE- less biindly