Seeing in Color, do fish?
Cameron Larsen
Fish do indeed perceive color. Every fly fisher knows that or
ought to know that. Like humans, the retina of a fish have rods
and cones. Cones are used in the day and rods at night. Color
vision evolved to help fish identify potential food. In the
environment of the fish, the background will either be the
bottom, the water itself, or if looking up for food it could be
the sky. The bottom is normally tannish olive to green. When
looking across the water, the background appears pale silver
blue. But if the water is off color due to algae or high water
one must take that into consideration as well. Skylight becomes
more important at dusk and dawn when it contains more reds.
Thus for opportunistically feeding game fish, flies with bright
or contrasting colors and/or a lot of flash will make them stand
out against the above mentioned backgrounds. The Mickey Finn,
tied with yellow and red, and a silver body is one of the most
effective attractor patterns. As for dry fly attractors , the
Royal Wulff is still hard to beat, with its red and peafowl body
and white wings. Black flies, because of their strong silhouette
also are easy for fish to spot. Let’s not forget patterns that
contain strands of flashabou or other tinsel that reflect light
when stripped or while drifting through the current are easy for
fish to spot.
The fly fisherman also must remember that color behaves
differently in water that it does when seen in the air. Water is
denser, and the colors are diffused quicker. Cloudy days where
there is less overall light will offer less visibility, and
colors will disappear quicker in the depths of the water. And the
clarity of water obviously greatly effects this as well. This is
important in fly selection because certain colors travel farther
in low light than others. Red is the first color to disappear,
usually at about 15 feet in clear water, followed by orange and
then yellow. Blues and greens are visible to the fish as long as
there is light. Yet silver and white will be brighter.
So while the Mickey Finn is obviously a great choice as an
attractor fly, it would not be as good a choice in murky water or
if fished deep. A better attractor might be a white Woolly Bugger
or White Marabou Muddler.
Color is also important to remember when matching the hatch.
Since fish use vision as the deciding factor to strike, one’s
offering must be the correct color. However, very small
differences in hue seem to not be much of a factor as most
insects will vary slightly in color as well. But if the intensity
of color the artificial fly has can be a factor. If the
artificial is more intense than the natural it is more likely to
catch fish. Why this seems to work is somewhat a mystery. It is
understood that fish see deeper into the ultraviolet range than
humans, so perhaps they are just seeing something we don’t. It
could also be due to the effect water has on colors. Perhaps
we’ll never know, but like many things in fishing, why something
works is not as important as just knowing that it does work.
While color is probably not the most important factor in a fish
striking a fly. The above considerations are nevertheless a good
thing to have in the back of your fly fishing mind.
Cameron Larsen is a retired commercial fly tier and fly fishing
guide. He now operates The Big Y Fly Co. at
http://www.bigyflyco.com
