82 REPORT OF COMMISSIONER OP FISH AND FISHERIES. 



they are wild and run away from the f.ood given them ; hence the neces- 

 sity of teaching a few fish to eat before more are added. The number 

 of fish that a pond of a given size can support depends upon the amount 

 of water and shiide and the temperature of the former. Ten thousand 

 fish are amxjle for a pond 10 by 50 feet, with water deepening from 3 

 inches to 3 feet. 



FOOD FOR FRY. 



Beef or sheep liver, ground or chopped to a pulp, seems to be the 

 most satisfactory artificial food for young trout. Fresh, hard boiled 

 eggs, grated fine, are good, but expensive. Efforts have been made to 

 produce a natural or living food, such as insect larvje and small crus- 

 taceans, and this may yet be accomplished for late spring and summer 

 feeding, but for feeding the fry during the first three or four months of 

 their lives, which is in the winter season, there is nothing better than 

 liver. Shad and herring roe, put up in sealed tin cans, have been used 

 to a limited extent with satisfiictory results, and it is believed that they 

 will furnish a wholesome and natural diet. 



The manner of feeding young fry is very important, as the losses from 

 improper feeding are greater than from all other causes combined. If 

 there is undue haste the water becomes polluted, or the food is so 

 distributed that some fish are prevented from getting their proper share. 

 Polluted water is very injurious to the young fish, being apt to produce 

 inflammation of the gills and a slimy, itching condition of the skin, 

 which often causes heavy mortality. 



The fry are ready to take food as soon as the sac is absorbed, the 

 time required for this depending upon the growth of the fish, which is 

 governed by the temperature of the water. Where the temperature is 

 regular at 53° they will take food in about 30 days after hatching, and 

 the time to commence feeding may be closely determined by watching 

 the movements of the fish. Before the sac is entirely absorbed they 

 will begin to break uj) the school on the bottom of the trough and 

 scatter through the water, rising higher and higher from the bottom 

 each day, until they can balance themselves gracefully in a horizontal 

 position, all heading against the current and swimming well up in the 

 water. By dropping some small bits of cork or the nap from red flannel 

 on the surface of the water it can be determined if they are ready for 

 food; if they strike at the pieces as the current carries them down it 

 is evident they are hungry. 



The liver is prepared by chopping it very fine and, if necessary, 

 mixing it with water, in order that it may be distributed evenly. It 

 should be given to the fish by dipping a feather into the liver and 

 gently skimming it over the surface of the water. After the fish grow 

 to be 1^ to 1^ inches long they begin to take up the food that settles 

 on the bottom of the trough; ilt is then not necessary to mix the food 

 with water, and it can be given by hand. The young fry are fed five 

 or six times a day and the food given slowly and sparingly. After they 



