Well perch in my area are an elongate fin fish very similar to walleye in shape and finnage. They are a darker green on top blending to a white belly, with dusky black over shaded bars not quite reaching the belly. the pectoral and anal fins can be a vivid orange to a golden yellow color depending on sex.
There can be in my opinion no mistaking this little jewel of the frying pan for me!
By the way, perch in my area (Yakima), run average size (6 to 10"), but i have the lucky fortune to have a private pond to fish which produces perch 10 to 17" with regularity. (mostly the 12" variety, its a little jewel of a pond about 3 acres or so)
Black crappie