The
redear sunfish also known as the
shellcracker,
Georgia bream,
cherry gill,
chinquapin,
improved bream,
rouge ear sunfish and
sun perch, is native to the southeastern
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
, but since it is a popular sport fish it has been
introducedAn introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
to bodies of water all over
North AmericaNorth America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
. It generally resembles the
bluegillThe Bluegill is a species of freshwater fish sometimes referred to as bream, brim, or copper nose. It is a member of the sunfish family Centrarchidae of the order Perciformes.-Range and distribution:...
except for coloration and somewhat larger size. It is dark-colored dorsally and yellow-green ventrally. The male has a cherry-red edge on its
operculumThe operculum of a bony fish is the hard bony flap covering and protecting the gills. In most fish, the rear edge of the operculum roughly marks the division between the head and the body....
; females have orange coloration in this area. The adult fish is between 20 and 24 cm (7.9 and 9.4 in) in length. Max length is 43.2 centimetres (17 in), compared to a maximum of about 40 centimetres (15.7 in) for the bluegill.
The favorite food of this species is
snailSnail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...
s. These fish are bottomfeeders, meandering along lakebeds seeking and cracking open snails and other shelled creatures. The fish has thick
pharyngeal teethPharyngeal teeth are teeth in the pharyngeal arch of the throat of cyprinids, suckers, and a number of other fish species lacking teeth.Popular aquarium fish such as goldfish and loaches have these structures. Members of the Botia genus such as clown loaches are known to make distinctive clicking...
, hard, movable plates in its throat, which allow it to crunch
exoskeletonAn exoskeleton is the external skeleton that supports and protects an animal's body, in contrast to the internal skeleton of, for example, a human. In popular usage, some of the larger kinds of exoskeletons are known as "shells". Examples of exoskeleton animals include insects such as grasshoppers...
s. It is even capable of opening small
clamThe word "clam" can be applied to freshwater mussels, and other freshwater bivalves, as well as marine bivalves.In the United States, "clam" can be used in several different ways: one, as a general term covering all bivalve molluscs...
s. The specialization of this species for the deep-water, mollusk-feeding niche allows it to be introduced to lakes without the risk of competition with fish that prefer shallower water or surface-feeding.
In recent years, the stocking of redear has found new allies due to the fish's ability to eat
quagga musselThe quagga mussel is a subspecies of freshwater mussel, an aquatic bivalve mollusk.It is one of seven Dreissena species and has an average life span of 3 to 5 years....
s, a prominent
invasive species"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
in many freshwater drainages.
During spawning, males congregate and create nests close together in colonies, and females visit to lay eggs. The redear sometimes hybridizes with other sunfish species.
The redear sunfish is also located in many marsh wetlands of freshwater.
Fossil record
The redear sunfish is the first-known species of
CentrarchidaeThe sunfishes are a family of freshwater ray-finned fish belonging to the order Perciformes. The type genus is Centrarchus . The family's 27 species includes many fishes familiar to North Americans, including the rock bass, largemouth bass, bluegill, pumpkinseed, and crappies...
based on fossil records, as old as 16.3 million years, dating back to the
Middle MioceneThe Middle Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene....
http://paleodb.org/cgi-bin/bridge.pl?action=checkTaxonInfo&taxon_no=83690&is_real_user=1.
External links