'ebruary, 1921 
FOREST AND STREAM 
69 
DO FISH DISTINGUISH FLY COLORS? 
THIS QUESTION IS RAISED NOT WITH THE IDEA OF TAKING ANY JOY OUT 
OF THE FLY-TIER’S LIFE BUT MERELY AS A MATTER OF CURIOSITY 
By M. LUCKIESH 
TOW often, on wintry evenings, have 
"H I enjoyed looking over my fishing 
tackle with its gaudy palette of col- 
■ed baits and as often there has arisen 
ie question, “Do fish distinguish 
>lor”? Such a query naturally forces 
self upon one whose activities happen 
i be confined largely to various aspects 
: color. However, I raise this question 
jre not with the purpose of taking any 
: the joy out of the sportsman’s life, 
it merely to present briefly what is 
nown concerning the color-vision of 
dies. 
It is known that the visual sense of 
wer forms of animal life differs in 
any cases from that of normal man 
id a vast amount of investigation has 
wealed the fact that the visual sense 
: man is generally more highly de- 
iloped than that of most lower forms 
: life, as might very well be expected, 
wing to the difficulties involved in the 
ivestigation of the vision of animals, in- 
icts, etc., the results in many cases are 
(complete and conflicting; however, 
lough is known regarding the vision of 
;hes to be of some interest to the fish- 
’man. Furthermore, regardless of our 
rejudices, we should appreciate that 
dentific investigations must be given 
uch more weight than results obtained 
:om uncontrolled and unsystematic ex- 
sriments with various fishbaits, in vari- 
as waters, on different days, and amid 
;her variable conditions. 
Man sees brightness whether color- 
lind or not. A person with normal vi- 
on sees color superimposed upon 
rightness. In other words, a rainbow 
ppears to a color-blind person to be a 
dorless band brighter in the middle 
yellow) and shading off gradually to 
wer brightnesses at the edges (red and 
iolet) . A red cherry appears of the 
ime color as the foliage to a totally 
)lor-blind person, but the cherry would 
merally differ in brightness from the 
foliage. Obviously the color-blind per- 
son also has form to guide him. If red 
and blue were presented to him he would 
note that they were different only as to 
brightness. There are many persons 
who are partially color-blind, red-blind- 
ness being the most common Lower 
forms of life exhibit visual senses of all 
classes represented by the totally color- 
blind, partially color-blind, and normal. 
T HERE is strong evidence in the re- 
sults of many investigations, that 
fishes distinguish brightness or lu- 
minosity and not color; in other words, 
that their vision corresponds roughly to 
that of the color-blind human being. 
Such experiments are carried out by the 
use of food on colored tiles, forceps, etc., 
and, of course, care is taken to eliminate 
odor, position, habit, etc., from vitiating 
the results. Numerous investigators 
have obtained no convincing proof that 
fishes discriminate color, but that they 
certainly distinguish differences in lumi- 
nosity. For example, in one case food 
was placed on colored tiles and the fish 
took it readily from white and pale blue 
tiles and less readily from dark red and 
dark blue tiles. Obviously the results 
can be explained by brightness differ- 
ences alone. 
One investigator used dark red larvae 
and colored imitations made of wool. The 
fish appeared to show a decided prefer- 
ence for the red. In another case, two 
forceps were used, respectively green and 
red, and to the red one food was always 
attached. These two forceps were placed 
in the two compartments into which the 
tank was divided. Their positions were 
reversed in a haphazard manner and the 
fish was made to enter one compartment 
first during half the trials and the other 
during the other trials. The food odor 
was present on the empty forceps and 
various other details were taken care of 
in a scientific manner. The fish never 
failed to bite the red one. In brief, the 
evidence gained in this investigation in- 
dicated that the fish (a chub) distin- 
guished color. The fish also discriminat- 
ed red from blue. 
Stained food has been used with some 
indication that fishes discriminated 
color somewhat as well as brightness. 
Other experiments have been conducted 
with beams of colored light projected 
through the water and the number of 
fish which gathered in the different 
beams was taken as evidence of color 
discrimination. However, it is impossi- 
ble, without an accurate knowledge of 
the sensibility of the visual apparatus of 
fishes, to know the relative brightnesses 
of these lights and colors as they appear 
to the fishes, to conclude definitely 
whether or not the fish reacted to 
brightness or to color differences or to 
both. 
Other investigators have used colored 
imitation baits with the general conclu- 
sions that their visibility to fish de- 
pended upon their luminosity or bright- 
ness and not upon their color. 
The writer once was having excellent 
luck with a red and yellow bait whei’e 
bass were plentiful. For the sake of ex- 
periment this bait was replaced with cne 
of the same form and approximately of 
the same brightness, namely a dark and 
a light gray. No change of luck wa3 
experienced. 
I N a brief article the vast amount of 
excellent and well controlled scientific 
investigations cannot be discussed 
fully. In the foregoing only a few chief 
points have been garnered from some 
of the work, with the hope that sports- 
( CONTINUED ON PAGE 83 ) 
Sometimes it seems to the angler who makes his own flies that a fish is tempted by the gorgeous color of his creations 
