Redear Sunfish
Redear are deep-bodied sunfish similar to bluegills and have a relatively small mouth. Color ranges from dark olive green above to almost white on the belly. The dorsal fin is normally equipped with 10 spines and it is broadly connected to the soft dorsal fin. The earflap has a distinct red edge.
 
Snails are often a major food item, which explains the name "shellcracker." Insects area also part of their diet, although they rarely rise to the surface as other sunfish. Redears prefer the bottom of warm waters heavy with aquatic vegetation. Sexual maturity is reached by the end of their second year. Spawning occurs in late spring or early summer on saucer-shaped depressions in deeper water than most sunfish.
 
The following is courtesy of Florida Fish and Wildlife Conservation Commission:
 
Appearance: A bright red mark on the back edge of the gill cover is very distinctive.
 
Habitat:  Redear prefer hard bottoms, congregating in deeper water than bluegill.
 
Behavior:  They prefer snails and clams, giving them their common nickname. Shellcracker grow larger than bluegill, with fish over 1 pound common.
 
State Record:  4.86 lbs. Big Catch: 12 inches or 2.25 lbs.