''Crystallaria'' is a genus of freshwater
ray-finned fish
Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species.
The ray-finned fishes are so called because their fins are webs of skin supported by bony or h ...
which is classified in the
subfamily Etheostomatinae
Etheosomatidae is a species rich subfamily of freshwater ray-finned fish, the members of which are commonly known as the darters. The subfamily is part of the family Percidae which also includes the perches, ruffes and pikeperches. The famil ...
, commonly known as the darters, part of the
family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
Percidae
The Percidae are a family of ray-finned fish, part of the order Perciformes, which are found in fresh and brackish waters of the Northern Hemisphere. The majority are Nearctic, but there are also Palearctic species. The family contains more than ...
which also includes the
perch
Perch is a common name for fish of the genus ''Perca'', freshwater gamefish belonging to the family Percidae. The perch, of which three species occur in different geographical areas, lend their name to a large order of vertebrates: the Per ...
es,
ruffes and
pikeperches. They are found in the
Mississippi River
The Mississippi River is the second-longest river and chief river of the second-largest drainage system in North America, second only to the Hudson Bay drainage system. From its traditional source of Lake Itasca in northern Minnesota, it ...
basin from Ohio to Minnesota and in southern Mississippi, northern Louisiana, and southeastern Oklahoma, and on the Gulf Slope of Escambia, Mobile Bay, and the
Pearl River
The Pearl River, also known by its Chinese name Zhujiang or Zhu Jiang in Mandarin pinyin or Chu Kiang and formerly often known as the , is an extensive river system in southern China. The name "Pearl River" is also often used as a catch-all ...
drainages. They have now been extirpated from Ohio, Kentucky, Indiana, and Illinois.
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Taxonomy
''Crystallaria'' is the sister taxon
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree.
Definition
The expression is most easily illustrated by a cladogram:
Taxon A and ...
of the genus ''Ammocrypta
''Ammocrypta'' is a genus of freshwater ray-finned fish, commonly known as the sand darters, which is classified in the subfamily Etheostomatinae, part of the family Percidae which also includes the perches, ruffes and pikeperches. The species ...
'' and together these genera are the sister taxon of the clade consisting of the speciose genus ''Etheostoma
''Etheostoma'' is a genus of small freshwater fish in the family Percidae native to North America. Most are restricted to the United States, but species are also found in Canada and Mexico. They are commonly known as darters, although the term "d ...
'' and ''Nothonotus
''Nothonotus'' is a genus or subgenus of freshwater ray-finned fish, a darter from the subfamily Etheostomatinae, part of the family Percidae, which also contains the perches, ruffes and pikeperches. It is endemic to the southeastern United S ...
''. Some authorities regard ''Crystallaria'' as a subgenus
In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus.
In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed betw ...
of ''Ammocrypta''.
Species
Currently, two species in this genus are recognized:
* '' Crystallaria asprella'' D. S. Jordan, 1878 (Crystal darter)
* '' Crystallaria cincotta'' S. A. Welsh & R. M. Wood, 2008 (Diamond darter)
References
Etheostomatinae
{{Percidae-stub