| Steve,
I have been researching this but can’t find a study on what wavelengths of light remain visible at low light levels. The ERC website has some good links to muskie biology. According to most of the studies, muskies don't have cones (color receptors) for the shorter wavelengths of light (blue and purple). It also says a muskie has a yellow filter in its cornea which act kind of like the yellow sunglass lens's and increases contrast.
I said a guide told me orange is the last color visible before complete dark, he writes for Esox angler. Here is my reasoning on why he said this. Light colors are different than pigment colors. To get yellow light you have to combine red and green. The lake we were fishing was clear with a slight algae bloom. The algae would absorb some of the green light thus making colors closer to red being more visible Thus orange.
Here is a site that has some good info on muskie color vison I found through the ERC website.
http://www.trentu.ca/muskie/biology/biol07.html
So, muskies can see colors, but not into the blue end of the spectrum (blues and purples probably appear as grey to them). The best colors for muskies are in the red-orange-yellow-green portions of the spectrum. Interestingly, muskies also have a distinctly yellow lens and cornea that helps filter out the shorter wavelengths (Bridges, 1969)
|
Posts: 32885
Location: Rhinelander, Wisconsin | We are discussing lure colors here, so what is reflected back to the eye is what is important to the discussion. All other light is absorbed by the bait and the color reflected represents the bait color. If that color has been filtered out by the water's natural prism action, then a representative shade of grey to black will be available to the eye.
Another factor is that the cone cells in the fish's eyes extend on a 'sun clock' basis, and retract the same way. It's probable that the muskie is operating nearly totally on rod vision by dusk, anyway, so color is irrrelevant at that point. Contrast is king, no matter what the discussion, in my humble opinion.
Also, most of the light is reflected back from the surface late evening due to the sun angle. Light on the surface isn't what's available under the surface, even just a few inches down.
Add to that the fact the muskie is looking up most of the time, and you have the total mental image necessary to make a color/contrast judgement.
Some examples of what I mean by all of this:
1) The Color of Objects
Here we consider the color of an object illuminated by white light. Color is produced by the absorption of selected wavelengths of light by an object. Objects can be thought of as absorbing all colors except the colors of their appearance which are reflected. A blue object illuminated by white light absorbs most of the wavelengths except those corresponding to blue light. These blue wavelengths are reflected by the object.
2) The Eye and Color Sensation
Our perception of color arises from the composition of light - the energy spectrum of photons - which enter the eye. The retina on the inner surface of the back of the eye contains photosensitive cells. These cells contain pigments which absorb visible light. Of the two classes of photosensitive cells, rods and cones, it is the cones that allow us to distinguish between different colors. The rods are effective in dim light and sense differences in light intensity - the flux of incident photons - not photon energy. So in dim light we perceive colored objects as shades of grey, not shades of color.
3) The light spectrum is well known. "ROY G. BIV" is an acronym used to remember the colors from one end to the other. From left to right the letters stand for: Red, Orange, Yellow, Green, Blue, Indigo, and Violet. A mixture of all the colors makes white light. That is, if one were to take 7 flashlights, each of which was giving off one of the listed colors, and shine all the different colors on a white wall, the spot of light would be white! A white light, therefore, gives off all the colors.
4) Absolutely perfectly clear water acts as a selective filter. If one were to suspend a white spot light above the surface with perfect vertical light penetration throughout the water column of a tank of water that was 100' deep, the colors from the white light would be filtered out selectively one-by-one. It is gradual. For example, most of the red is gone from the light after 10 feet. Some of the orange is gone. Less of the yellow is lost, etc. At 25' most of the orange is gone. At 35' most of the yellow is gone. This continues through the spectrum until all that is left is violet light and that fades out after hundreds of feet.
5) Fish color vision is probably very different from ours. Contrast betweeen the color of the foreground and the background is important for their sight.
|
