556 U. S. BUREAU OF FISHERIES 
to review the status of current activities. By concentrating hatchery 
production in comparatively restricted areas, positive results can gen- 
erally be achieved. The cost of such local benefits may be excessive 
and judgment. must be based upon the benefits accruing to fish popu- 
lations as a whole. . 
The basic principles of animal husbandry are naturally applicable 
to the breeding of fish. Increased attention has therefore been given 
to selection of hatchery breeding stock and to the development of 
suitable diets. Sanitation has been emphasized as one of the best 
means of preventing undue mortality, and experimentation, with refine- 
ments in technique and equipment, has been conducted. ! —- 
The emphasis during the year under review has been in the direction 
of improving existing hatcheries as to plant, equipment, and operating 
efficiency, with less thought to any program of expansion. 
SPECIES PROPAGATED 
The Bureau hatcheries propagated, or handled in salvage activities, 
50 different species. The larger percentage of this list. covered the 
fresh-water and anadromous types, although the salt-water groups 
accounted for the major part of the output numerically, 
Dolly Varden trout appeared in the listing for the first time in sey- 
eral years. There has been relatively little change, however, in the 
category of species propagated, beeause of the fact that the list already 
covers practically all forms which are readily amenable to methods of 
artificial culture. 
Several varieties, such as the yellow or white perch, are propagated 
as aside line at hatcheries primarily intended for other species. These 
perch would not be handled unless the facilities were available during 
the off season on the hatching of shad. 
The selection of the game species to be propagated at each of the 
hatcheries has been predicated upon a demand, which is an outgrowth 
of the geographical range of species. This takes into consideration 
the fact that many species have been transplanted beyond their nor- 
mal range. Very little work of transplanting has been undertaken in 
recent years beeause of the belief that the fish population of the coun- 
try has been quite thoroughly dispersed into the zones to which the 
species can be adapted. There is further evidence of the fact that 
distinctions between game and nongame species have largely broken 
down. Such distinctions are recognizable now only in the State fish 
and game laws, which frequently make an arbitrary separation of the 
two groups. 
Catfishes (Silwridae) : 
Yellow cat (Opladelus olivaris). 
Spotted channel cat (/ctalurus punctatus). 
Bullhead (Ameturus nebulosus). 
Buffalofish (Catostomidae): Common buffaloes: (/ctiobus sp.). 
Shad and herring (Clupeidae) : 
Shad (Alosa sapidissima). 
Glut herring (Pomolobus aestivalis). 
Whitefishes and Lake herring (Coregonidae) : 
Common whitefish (Coregonus clupeaformis). 
Lake herring, cisco (Leucicthys sp.). 
Salmons and trouts (Salmonidae): 
King, chinook, or quinnat salmon (Oncorhynchus tschawytscha). 
Chum salmon (Oncorhynchus keta). 
Coho, or silver salmon (Oncorhynchus kisutch). 
