The green sunfish is blue-green in color on its back and sides with yellow-flecked bony-ridged (ctenoid) scales, as well as yellow coloration on the ventral sides. The gill covers and sides of the head have broken bright blue stripes, causing some to mistakenly confuse them with bluegill. They also have a dark spot located near the back end of the dorsal fin, the bases of the anal fins. and on the ear plate. It has a relatively big mouth and long snout that extends to beneath the middle of the eye. Its pectoral fins are short with rounded edges containing 13-14 pectoral fin rays, a dorsal fin with about 10 dorsal spines, and a homocercal tail. The typical length ranges from about 3-7 in and usually weighs less than a pound. The green sunfish reaches a maximum recorded length of about 12 in, with a maximum recorded weight of 2.2 lb. Identification of sunfish species from one another can sometimes be difficult as these species frequently hybridize.

Source
Wikipedia