Perch aren't even listed as being in this Illinois State Park. But I've been catching them through the ice for the last couple of years. I don't think they were stocked by DNR.
How can you tell if they have eggs? Belly didn't look like it was bulging.
Could be a male? When they get close to peak egg maturation it's pretty obvious.
These two fish are from my fish farm. Top is a male bottom is a female. Both the same age. Males are runts compared to the females. During the spawning period one can push out milt with some pressure with the males along with the obese appearance of the female due to eggs. Up to 30 percent of a female's body weight can be eggs at peak spawning time.
They have differences in the appearance of their urogenital openings but it's not 100 percent. Only way to tell them apart 100 percent correctly when they are not in the spawning phase is by the use of a small diameter catether tube to see if you can extract some eggs.