Crystal darter
Encyclopedia
The crystal darter, Crystallaria asprella, is a small North America
North America
North 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...

n fish found in small, moderate, and swift rivers in the drainage basins of the Mississippi
Mississippi River
The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...

 and Ohio River
Ohio River
The Ohio River is the largest tributary, by volume, of the Mississippi River. At the confluence, the Ohio is even bigger than the Mississippi and, thus, is hydrologically the main stream of the whole river system, including the Allegheny River further upstream...

s. It is now extirpated from a majority of its range along the Ohio River. The crystal darter and the diamond darter
Diamond darter
The diamond darter, Crystallaria cincotta, is a species of freshwater fish of the darter family. It is named for the sparkling light it reflects during nighttime collections, the diamond darter was first described in 2008 and is only the second known member of its genus, which also includes the...

 are the only members of their genus.

Other Names

Until recently, the crystal darter's species name was Ammocrypta asprella, but this name is now considered invalid. When this fish was discovered in 1878, it was given the name Pleurolepis asprellus.

Appearance

The crystal darter can grow to 5 inches in length. It is olive-colored to tan with four dark saddles extending downward to its lateral line
Lateral line
The lateral line is a sense organ in aquatic organisms , used to detect movement and vibration in the surrounding water. Lateral lines are usually visible as faint lines running lengthwise down each side, from the vicinity of the gill covers to the base of the tail...

, a brownish stripe, and a whitish belly. Its maximum reported age is 3 years.

Conservation

The crystal darter is listed as vulnerable by the IUCN on its Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...

 because of "a decline in area of occupancy, extent of occurrence and/or quality of habitat." It is also listed as a special concern species in Minnesota
Minnesota
Minnesota is a U.S. state located in the Midwestern United States. The twelfth largest state of the U.S., it is the twenty-first most populous, with 5.3 million residents. Minnesota was carved out of the eastern half of the Minnesota Territory and admitted to the Union as the thirty-second state...

 by the Minnesota Department of Natural Resources
Minnesota Department of Natural Resources
The Minnesota Department of Natural Resources is the agency of the U.S. state of Minnesota charged with conserving and managing the state's natural resources. The agency maintains areas such as state parks, state forests, recreational trails, and recreation areas as well as managing minerals,...

 and in Arkansas by the Arkansas Game and Fish Commission; as an endangered species in Wisconsin
Wisconsin
Wisconsin is a U.S. state located in the north-central United States and is part of the Midwest. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. Wisconsin's capital is...

 by the Wisconsin Department of Natural Resources
Wisconsin Department of Natural Resources
The Wisconsin Department of Natural Resources is an agency of the state of Wisconsin. Its purpose is to preserve, protect, manage and maintain the natural resources of the state. The WDNR has the authority to set policy for itself and to recommend regulations for approval by the State Legislature...

 and in Missouri
Missouri
Missouri is a US state located in the Midwestern United States, bordered by Iowa, Illinois, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas and Nebraska. With a 2010 population of 5,988,927, Missouri is the 18th most populous state in the nation and the fifth most populous in the Midwest. It...

 by the Missouri Department of Conservation
Missouri Department of Conservation
The Missouri Department of Conservation and the Missouri Conservation Commission were created by Article IV Sections 40-42 of the Missouri Constitution, which were adopted by the voters of the state in 1936 as Amendment 4 to the constitution...

; as an extirpated species in Illinois by the Illinois Department of Natural Resources
Illinois Department of Natural Resources
The Illinois Department of Natural Resources is a cabinet-level department of the state government of Illinois. It is headquartered in the state capital of Springfield...

; and as a tier 1, or critically impaired, species in Mississippi
Mississippi
Mississippi is a U.S. state located in the Southern United States. Jackson is the state capital and largest city. The name of the state derives from the Mississippi River, which flows along its western boundary, whose name comes from the Ojibwe word misi-ziibi...

 by the Mississippi Department of Wildlife, Fisheries and Parks
Mississippi Department of Wildlife, Fisheries and Parks
The Mississippi Department of Wildlife, Fisheries and Parks , formerly known as the Mississippi Game & Fish Commission, is an agency of the government of the U.S...

because of "extreme rarity (5 or fewer occurrences or very few remaining individuals or acres) or because of some factor(s) making it vulnerable to extirpation."

External links

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