Yes, we’ve kept yellow perch in the jumbo aquarium at In-Fisherman headquarters, along with almost every North American gamefish. Once accustomed to captivity, each species demonstrates certain behavioral characteristics that differentiate it from other species.

Perch are noteworthy for their watchful curiosity, as well as their huge appetite. The only fish that cleaned out the minnows faster was Steve Hoffman’s blue catfish, and then that rascal turned on the jumbo bluegill, crappies, and perch that abided with it for a time.

When we toss in a handful of minnows, the perch are immediately aware of the prey and smoothly close in, gliding along several inches above the bottom. They move in close, then make a kind of Jackie Chan move, combining a greedy lunge with a bass-like engulfing motion to take a minnow into their mouths.

Many of these characteristics verify what science tells us about the nature of perch and matches our experiences when fishing them through the ice and in open water. Let’s begin with a look at the sensory systems of the yellow perch.

Vision

The eyes of yellow perch are medium-size and set on the side of their heads. This offers better peripheral vision and good long-range vision, more like a pike than a bluegill. This alerts them quickly to potential prey and potential danger. On the other hand, they can’t focus so well at close range like crappies or bluegills, lacking the specialized muscles on the lens that move it outward to view close objects, like the zoom lens on a camera.

Perch possess color vision, and their fairly close relationship to walleyes suggests that they’re sensitive to wavelengths in the orange, chartreuse, and green range. And we know that silver and gold flash can be deadly as well.

Perch, however, lack the wonderful reflective eyes of the walleye and see poorly after dark. Indeed, fish in the aquarium squat on the bottom and scoot out of sight when the lights are turned on. Walleyes, in contrast, always cruise about actively, then shoot to the bottom and sit motionless when the lights go on. This makes small perch a prime prey for walleyes who often occupy the same deep rocky structures and major flats during winter.

Hearing

Most fish are thought to have an excellent sense of hearing, based on the structure of their inner ear and on behavioral tests with some species (none have been done on perch). Underwater sounds travel so far and so fast (almost five times faster than in air) that fish are surrounded by sound. We suppose that, like people at a party, fish tune out many of the ambient sounds around them, responding to those that represent food or danger, or that arouse curiosity.

Like most North American gamefish, perch are intermediate in hearing ability, acuity, and range, based on the structure of their hearing system. The structure of their inner ear suggests that perch probably detect sound waves from about 10 cycles per second Hertz to perhaps 1,000 Hertz.

Lateral Line Sense

Midway down the side of most fishes exists a series of pores we call the lateral line. This is a sensory array that picks up vibration carried by low-frequency water displacement. The fish’s brain translates this sensory input into information it can use, about the approach and movements of predators and prey. Vibration seems to be a powerful force in the world of perch, and certainly it affects all fish more than we can imagine. Humans completely lack this sense, which provides fish and aquatic amphibians with information about their environment.