While herping in southern Illinois this month, I caught this sunfish which is endemic to the southern United States. It is the only species in the monospecific genus Centrarchus.
The Flier is similar in appearance to a Crappie. It is deep-bodied and saucer-shaped. It is generally olive-green to brassy in color, with numerous black spots on sides arranged in rows on adults. They reach a total average length of 5 to 7 inches, with a maximum size of about 8 inches.
Fliers often reside in dark, tannic, acidic backwaters of coastal swamps, creeks, ponds and canals. They thrive in areas with thick vegetative cover and can survive in locations with minimal levels of dissolved oxygen. Insect larvae, small crustaceans, worms, small fish and algae make up their diet.
A key identification characteristic of this fish when immature, is a dark eyespot, which has a reddish border on the dorsal fin. This eyespot disappears as the fish grows. Fish biologists have speculated the dark spot, when coupled with their eye, gives the appearance of a much larger fish. This adaptation is believed to deter potential predators.
A Second World War United States Navy submarine was named the USS Flier after this fish.