60 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



When young salmon or trout first begin to feed they are quite unable 

 to swallow full-grown maggots, and small ones are obtained for them by 

 putting a large quantity of fly spawn with a small quantity of meat, 

 the result being that the maggots soon begin to crowd each other and 

 the surplus is worked off into the lower box before attaining great size. 

 ISTo attempt is, however, made to induce the young fish to swallow even 

 the smallest maggots until they have been fed a while on chopped 

 liver. 



Maggots are produced and used in considerable numbers, sometimes 

 as many as a bushel in a day. The fish eat them eagerly, and appear 

 to thrive on them better than on dead meat. Having great tenacity of 

 life, if not snapped up immediately by the fish they remain alive for a 

 day or two, and, as they wriggle about on the bottom, are almost cer- 

 tain to be finally eaten, which is a great gain in cleanliness and economy, 

 as the particles of dead flesh falling to the bottom are largely neglected 

 by the fish and begin to putrefy in a few hours and foal the troughs. 

 As the growth of maggots can be controlled by regulation of the tem- 

 perature, they may be kept all winter in a pit or cellar and used as food 

 for fish confined in deep tanks not easily cleaned. 



In the rearing of maggots the offensive odors of decaying flesh may 

 be partly overcome by putting it away in boxes, after the visits of the 

 iiies, and covering it with pulverized earth. Only flesh-eating maggots 

 have yet been tried, and the trouble may possibly be rectified by culti- 

 vating the larvae of other species, such as the house-fly, the stable fly, 

 etc., or a little white maggot known to grow in heaps of seaweed, if 

 their rate of growth is found to be satisfactory. 



Occasional use has been made of fresh fish for direct feeding, but when 

 thrown into the water after chopping it breaks up into fibers to such 

 an extent that it is not satisfactory, unless in a coarsely chopped form, 

 for the food of large fish. A few barrels of salted alewives have been 

 used, and, if well soaked out and chopped, they are readily eaten by the 

 larger fish and can be fed to fry, but are less satisfactory with the latter, 

 and, like fresh fish, break up to such an extent that they are only to be 

 regarded as one of the last resorts. 



Fresh-water mussels, belonging almost wholly to a species of Unio, 

 Tiave been occasionally gathered with nets or dredges in the lake close 

 to the station and opened with knives and chopped. The meat is 

 readily eaten by all fishes and appears to form an excellent diet. It is 

 more buoyant than any other article tried, sinks slower in the water, 

 and gives the fish more time to seize it before it reaches the bottom ; 

 but the labor involved in dredging and shelling is a serious drawback. 



During the seasons of 1886 and 1888 some use was made of mosquito 

 larva?, collected from pools of swamp water by means of a set of strain- 

 ers specially devised for the purpose and from barrels filled with water 

 disposed in convenient places near the reariug-troughs. The larva? (or 

 pupa?) were strained out and fed to the fish. N^o kind of food has been 



