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44 REPORT OF THE COMMISSIONER OF FISHERIES. 
There is in progress and now drawing to a conclusion an investi- 
gation of the habits of the common smelt, a fish which is of no little 
economic importance, partly as an object of fishery itself and more 
significantly as a source of food for the larger food and game fishes. 
It is generally known that many species of fish are destructive to 
the larve of mosquitoes, but, where public health is involved, it 
becomes of high importance to know definitely what fish are most 
effective in mosquito extermination and under what conditions is 
their efficiency greatest. In many cases, where the usual treatments 
of waters are impracticable because of expense or other sacrifice 
involved, it is convenient to rely upon the agency of small fish, 
provided there can be assurance that the result sought will be fully 
accomplished. It is possible that in particular cases partial failure 
to eliminate all mosquito larve can be turned into complete success 
through the introduction of other kinds of fishes that will be adapted 
to the particular condition of the pond or through measures taken 
to so change those conditions that the fish will have a better chance 
to obtain their prey. It is necessary then to study the comparative 
efficiency of the different species of fish and to ascertain how the 
efficiency of the more suitable species is affected by the various 
conditions of depth, vegetation, and débris. 
At the beginning of the fiscal year the Bureau issued an economic 
circular giving an account of the various species of fish that play 
an important part in mosquito extermination and at the same time 
it entered into cooperation with the Bureau of Entomology for a 
careful investigation directed to the ends just stated. The inquiry 
will be continued through the next fiscal year. 
In addition to its functions in mussel culture, and without hin- 
drance to them, the Fairport station is being utilized effectively in 
fish-cultural experimental work. Some of these experiments are 
being conducted with the game fishes that are favorite objects of 
cultural efforts. The purpose of these experiments is primarily to 
ascertain the conditions under which the fish may be reared to a 
market size in greatest numbers. 
During the spring of 1915 unusual success was attained in the 
hatching of the eggs of the buffalofish after artificial fertilization. 
' A number of the fry were peaed in a new station pond to be kept 
t 
under observation. Notwithstanding the raw state of the pond and 
other unfavorable conditions, more than 25 per cent of the fish, 
or about 45,000, were found to have survived when the pond was 
drawn in the fall, and some had attained a length of over 6 inches. A 
good many of the fingerlings were liberated and others were retained 
for further growth. A proportion of loss was experienced during the 
winter season, but the experiments are still in progress. Not all has 
been obtained that would be desired, but, as the first attempt at rear- 
ing buffalofish in capitivity, the success is such as to recommend the 
continued experimentation with a form that is well known as a com- 
mercial food fish of large size and of diminishing abundance. 
Quite interesting results have been attained too with the channel 
catfish (/ctalurus punctatus), a form that has hitherto baffled all 
attempts at propagation. Just at the close of the fiscal year the 
first successful attempt at propagation was in progress, but the fur- 
ther history of the experiment is a matter for a later report. 
