One of the most popular sport fish in the U.S. the Bluegill Sunfish is very colorful with light to dark blue on bright purple. Their gill covers are often blue with a black spot on the rear of the “ear flap” and have faint vertical bars on the sides. In breeding season, the breast of males is red. The mouth is small and when closed, barely reaches the front of the eye. Their overall body is deep for its length and compressed from side to side.