Eyeball to Eyeball

You’re eyeball to eyeball with a walleye surfperch. I love the yellow streak on the upper part of the iris. One of the ways we identify the walleye is by its large eye.

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Honestly, the eye doesn’t seem that large when viewed on live specimens in the wild. When I encountered a large male I got the idea to measure the proportional size of the eye and compare it with that of a close relative, the silver surf perch. I measured the height and length of the eye and the head, then calculated the ratio. In a fish with a proportionally bigger eye, the eye:head ratio will be a larger number.  Here are the results. Length: walleye = .33; silver = .22. Height: walleye = .38; silver = .34. The walleye has a proportionally larger eye, especially in the length dimension. The field guides are correct!