Adult length: 16 in (40 cm); bluegills may be distinguished from other sunfish by the dark spot at the base of the dorsal fin, vertical bars on their sides, and a relatively small mouth. The spiny dorsal fin usually has 10 spines (but may have as many as 11 or as few as 9), and is broadly connected to the soft dorsal. The anal fin has three spines. The back and upper sides are usually dark olive green blending to lavender, brown, copper, or orange on the sides, and reddish-orange or yellow on the belly. Colors are more intense in breeding males, and vertical bars may take on a reddish hue. One of the most distinguishing characteristics is the dark blue or black “ear” on an extension of the gill cover called the opercular flap.