Breakthrough research on how stripers see their prey

[Fish_Eye]

I was doing some research for an article recently and I found some fascinating information on the specifics of how stripers view their world.

Thanks to the work of Virginia Institute of Marine Science graduate student Andrij Horodysky and faculty advisor Dr. Rich Brill, we now know that the stripers has evolved to see swiftly moving prey in daylight while others, like weakfish, are adapted to see small, sluggish prey at night.

The striper’s color-sensitive cone cells move toward the surface of the retina during daylight hours, and retreat to make room for the contrast-sensitive rod cells at night. This “circadian rhythm” also changes with the seasons.

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 of around 50 (similar to the shutter speed in a camera), relatively fast for a fish, which allows them to track large, quick-moving prey like menhaden.

Compared to striped bass, weakfish have slow vision (around 25 cycles per second) and are more sensitive to contrast than color.

Horodysky states, “You’ve got two animals that are competing
for the same food. How do they do it? Stripers use color to see and feed during the day. Weakfish use contrast sensitivity to see at night.”

Another fascinating aspect of Horodysky’s research is that he and his collogues hypothesize that striped bass are often living in a visual world very different from the one that evolution prepared them for. History indicates that bay systems that stripers thrive in have gradually gotten murkier due to the runoff and the demise of oysters, mussels and aquatic vegetation. This means that although they are adapted to see—large, fast-moving fish like menhaden—they’re actually feeding on crabs, lobsters, and shrimp because they can find them easily in turbid water. The fact that menhaden have been over fished must enter into this equation as well.

In dark or dirty water, I always go for a chartreuse colored offering, now I know it’s effective because it's a color that is right in the middle of a striper’s visual range and it can easily be seen.

Pass me the pearl bomber.