Merwin: On UV Bass Baits and How Fish See Color

One of the most perplexing things in all of angling is how fish see and respond to color. And the more one learns about fish vision, the greater the puzzle becomes. That's because fish apparently do not see color the same way that humans do. You might logically think that a beautifully finished frog-pattern lure is eaten by a bass because the fish thinks it looks like a frog. But that's not necessarily so.

As most people know, the spectrum of visible light is composed of a variety of colors ranging from reds to deep violets. That spectrum includes ultraviolet light invisible to humans but visible to fish. There are some new soft-plastic baits out now [photo] with additives that fluoresce under UV or so-called black light. The color difference is striking.

Tightlines Lure Company in Missouri introduced these baits last summer. I have fished with some and can report that they do indeed work on largemouth bass. I have not yet fished them enough to say they work better than more conventional baits.

Even though the baits glow brightly under UV light, that glow is what humans see and is not necessarily what fish see with their different spectral response. It's going to take a lot of trial-and-error testing on the part of anglers to see if and how differently the new baits work.

Meanwhile, know the color problem pertains just as much to dry-fly fishing for trout, for example, as it does to bass fishing with soft plastics or anything else. Long-term trial and error creates certain successful traditions in lure choice. I might know that a yellow lure or fly works especially well in certain circumstances. But I don't know exactly why that is so, and not knowing has bugged me for a very long time.