The sun. [volume] (New York [N.Y.]) 1833-1916, 1907-06-16
DIET OF FISHES NEGLECTED
NOW UNCLE SAM PROPOSES 10
REMEDY THE OVERSIGHT.

Matter OF Importance 20 Fishes AMI
Also 10 Those VINO Eat Them -Sonc
cases In POlnt-PrObIem Of StocAIns.
1t is proposed by the Bureau Of Fisherir,
to take up a practically neglected subject
the proper dietary OF fishes. One OF tho.,
deputed by the bureau to inquire into tn,
subject said OF the Importance of the in.
vestigation:
Although agriculturists have lookoi
a~ssiduously after the improvement II
their stock by proper feeding, comparl-
lively little attention has been given -
the food OF our useful aquatic animals,
The bureau now recognizes that the entirc
! question Of the relation Of quantity ami
quality OF food TO the rate of growth ana
physical we'll being OF fishes needs much
more thorough investigation than it ha!
yet received.
This neglect 10 certainly not due TO the
slight economic Importance of the subject.
1t has been estimated that a 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 faoV
that a small fish pond, 90 by 40 feet. in
Indiana produced 1000 pounds Of black
bass and $50 pounds Of yellow perch in
fifteen months without being supplied
with artificial food. At the price Of eight
cents a pound, it was estimated that il the
natural waters o fIndiana had been relatively
only about q 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 1895. the year Of
this experiment, and a little more than
twice the value Of the wheat crop.
yet in spite OF the great possibilities
of lakes and streams from an economic
standpoint, most Of them receive little or
no attention except when Legislators
wrestle with the problem Of devising avs
for the protection Of fab and aquatic birds.
There is little doubt that il moro attention
we're given to Investigations relative TO
increasing the producing efficiency Of
lakes and streams many Of the protective
laws now on our statute books would be-
come super1uous.
Like other living organisms, fishes are
affected by both the quantity n ithe
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 condition OF those
that do survive.
Fish epicures nave persistently msin-
tanned that the flavor OF 3 poorly or i'm
properly fed fish is much inferior TO that
Of the right kind Of food. Baird cites an
experiment in which young trout, were
placed in three separate tanks and were
fed on different kinds Of food. The trous
in one tank were supplied with WORMS.
those In another with live minnows, while
those in the third we're fed upon water
flies.
aThe trout which subsisted upon worms
grew slowly and had a lean appearance,
those which were supplied with live min
nows became much larger, while those
which had flies alone given them attained
In a short time prodigious dimensions.
weighing twice as much as both the Others
together. 1t is, Of course. true that there
is a very marked difference, in the rate Of
growth OF trout even under apparently
the same food conditions.
Trout culturtsts, for instance. n Y
necessary TO sort the young trout OF a pond
at regular intervals after they are a few
months old. and separate the larger. pre-
weaker ones, in order TO keep the former
from preying upon the latter. But In
spite Of this apparently. contradictory
evidence there 10 little doubt that the
Ia the experiment / have cited was due
In some measure at least to the different
kinds Of food supplied.
"As long ago as 1858 Walton appreciated
the importance OF the quality OF the feed
ing ground, for he says: And certainly.
as some pastures breed larger sheep. 80
do some rivers, by reason OF the ground
over which they flow. breed larger trouts'
Francis QeoS) makes the assertion that
trout In one stream will be much larger.
hrmer. redder and better shaped than In
Others. This may. in a measure, be owing
to the greater abundance OF food, but |
have every reason to believe that it pro-
Deeds quite as much from the kim Of food
that they are enabled to obtain
"Thus IL is evident that a knowledge
OF both the quantity and kinds Of food
found In a stream or lake is Of very great
when It comes to the question
Of trout culture. This. doubtless. is true
also Of tho culture Of all other fishes. and
knowledge. IL is felt assured, would
prove very valuable in the introduction Of
O species Of fab into new waters.
III we know the kind Of food on which
the fish thrves best. and II we also know
the Quantity mt kinds Of food available
in the water to be stocked, then we can
attack the problem of stocking the water
in UGH a way as greatly to increase the
OF success. Until such knowledge
lie acquired, we must continue to expert