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Old 08-16-2007, 11:20 PM
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Default Re: Fish Vision Study

Horodysky's research shows that striped bass are most sensitive during daylight hours to a wide range of colors from blue to red, with a peak at chartreuse. They have a "flicker fusion frequency" (essentially the "shutter speed" of an eye) of around 50, relatively fast for a fish, which allows them to track large, quick-moving prey like menhaden.
One intriguing aspect of Horodysky's research is the disparity he's found between the prey items that striped bass are adapted to see— large, fast-moving fish like menhaden—and the items that actually occur in their stomachs—mostly small crustaceans like juvenile blue crabs and mysid shrimp.
Horodysky and his faculty advisors hypothesize that striped bass are living in a visual world very different from the one evolution prepared them for. That's because human activities in the Bay watershed and the demise of the native oyster have dramatically reduced the clarity of Bay waters Chesapeake Bay used to be very clear,says Brill. Now we've made it mucky. So we see the visual ecology of the Bay changing. Our argument is that over evolutionary time these fish have made certain visual choices, then suddenly find themselves in a visual environment they didn't evolve in.
I would have expected the total opposite.
What is most interesting is that they could possibly be adapting to the changing environment of the bay.

Some other cool stuff for those who have the time to read it.

This is Power point presentation on fish vision from the Rochester Institute of Technology computer science dept.
Credit Link

An article from sws can fish see colors. SWS article

Can Fish See Color?

Most scientists think so. Here's how it can work for you.

January 1, 1999
By George Poveromo

As any angler knows, artificial fishing lures come in a wide range of attractive colors and color combinations. Whether fish actually see color — and, more importantly, whether they react to it — has been an ongoing debate for quite some time. As one major manufacturer of offshore trolling lures once told me in confidence, "You can catch offshore fish on any lure color, since it's the action of the lure that attracts and provokes them into striking — not color."
At the opposite end of that spectrum, experts at inshore-lure companies believe fish can indeed distinguish colors. Their philosophy is that if their lures aren't ultra-realistic, they won't fool as many fish.
The Science of Vision
"A big factor is the color spectrum and what happens when light moves into the ocean," says Dr. Linda Farmer, director of the Undergraduate Program in Marine and Atmospheric Science for the University of Miami. "As light travels through the water, red, which is the longest wavelength, is absorbed first, followed by orange, yellow, green and blue and, eventually, indigo and violet [the shortest wavelength], leaving no sunlight below a certain depth. Red will appear as a faint black. The color violet will remain intact the longest." It should be noted that how far down these colors penetrate varies based on water clarity, the amount of light and other factors.
The complexity of vision in fish varies from species to species. Some experts believe that offshore fish such as billfish, tuna, wahoo and dolphin are colorblind and only distinguish objects that contrast with the background they see. These fish are thought to possess two visual pigments, sensitive to blue and yellow light. According to Farmer, some inshore fish have more than two pigments. Fish with four pigments can detect many colors and can distinguish bright and dark objects against any background. Armed with this knowledge, I discussed my approach with some successful anglers.
Offshore Evidence
"The purple-silver-black combo is the ticket," says Frank Johnson of Mold Craft. "If I had to choose just one lure color for billfish, it would be purple, hands down. We not only sell more lures in this primary color, but we've got guys using it all over the world, and saying it works. There has to be something to it."
Dissecting the idea that offshore fish see more shades than colors, it could be argued that purple may indeed offer a sharper contrast against a bright sky or blue ocean. One could also say that the purple hues closely resemble small tunas, on which billfish prey. Could it be the "match the hatch" theory at work? Or are fish more keyed in to the color patterns of their forage, rather than the type of forage?
I've long had confidence in trolling lures in colors that mimic the natural forage. My go-to colors are all-blue or blue-white, which I think mimic flying fish. When peanut dolphin are abundant, I'll add a few green-blue-yellow combinations to our spread to imitate dolphin.
The Inshore Spectrum
Eric Bachnik is chief operating officer of L & S Bait Company in Largo, Florida — makers of MirrOlure — and a light-tackle inshore angler.
"Our top-selling MirrOlure pattern for 65 years has been the red head-white body," says Bachnik. "Perhaps it appears like an injured baitfish. That's followed closely by our natural scaled sardine pattern.

Color By Number
General guide: percentage visible at depth.

Red 10 feet 6.5% - 30 feet 0.025%
Orange 10 feet 50% - 30 feet 12%
Yellow 10 feet 73% - 30 feet 40%
Green 10 feet 88% - 30 feet 69%
In clear water, fish can see a natural-forage-pattern lure better and it resembles what they're eating."

Of the vast colors and combinations offered by his company, Bachnik believes that in cloudy or tannic waters, fish can see gold and chartreuse patterns better. "In these conditions, fish rely heavily on vibrations," says Bachnik. "On dark nights, I like all-black, black-silver or purple. Even on moonless nights, there will be some light that helps fish see and dial in on the silhouette. On a bright night, I'll choose lures with holographic or mirror inserts."
When plugging inshore, I "match the hatch." If there's an abundance of a specific bait, chances are gamefish will be tuned into those colors. I often go with the red head-white body lure if there is a lack of bait. Two things are certain: Gamefish respond to lure color, and we'll still continue to fish our go-to lures. But experimenting with color in the quest to find a knockout lure is a challenge we seem to enjoy.
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