The woundfin (''Plagopterus argentissimus'') is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

minnow Minnow is the common name for a number of species of small freshwater fish, belonging to several genera of the families Cyprinidae and Leuciscidae. They are also known in Ireland as pinkeens. Smaller fish in the subfamily Leusciscidae are c ...

endemic to the

Virgin River The Virgin River is a tributary of the Colorado River in the U.S. states of Utah, Nevada, and Arizona. The river is about long.Calculated with Google Maps and Google Earth It was designated Utah's first wild and scenic river in 2009, during the ...

of the southwestern United States. It is the only species in the

monotypic genus In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

''Plagopterus''.

Description

The woundfin is a small slender, silvery minnow, with a flattened head and belly, long snout, leathery skin, and no scales. There are

barbels In fish anatomy and turtle anatomy, a barbel is a slender, whiskerlike sensory organ near the mouth. Fish that have barbels include the catfish, the carp, the goatfish, the hagfish, the sturgeon, the zebrafish, the black dragonfish and some s ...

on the corners of its lips, and its common name likely comes from the first spinous ray of its

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through c ...

, which is sharp-pointed. Its maximum length is rarely more than 7.5 cm (3 in)."''Plagopterus argentissimus''"
Arizona Game and Fish Department. 2001. Retrieved on July 16, 2006. It can be distinguished from spikedace and spinedace by presence of barbels.

Distribution

Historically, the woundfin occupied much of the lower

Colorado River The Colorado River ( es, Río Colorado) is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and northern Mexico. The river drains an expansive, arid watershed that encompasses parts of seven U.S. s ...

basin, including two

tributaries A tributary, or affluent, is a stream or river that flows into a larger stream or main stem (or parent) river or a lake. A tributary does not flow directly into a sea or ocean. Tributaries and the main stem river drain the surrounding drainag ...

, the Virgin River and part of the Gila River; however,

habitat destruction Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

through dams and water development has led to its

extirpation Local extinction, also known as extirpation, refers to a species (or other taxon) of plant or animal that ceases to exist in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinct ...

from these regions. In addition, several

introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived ther ...

, most notably the

red shiner The red shiner or red-horse minnow (''Cyprinella lutrensis'') is a North American species of freshwater fish in the family Cyprinidae. They are deep-bodied and laterally compressed,Farringer R.T., III, A.A. Echelle, and S.F. Lehtinen. 1979. Repr ...

(''Cyprinella lutrensis'') have contributed to a decrease in the woundfin's Virgin River population. The woundfin is currently federally listed as an endangered species, while the

United States Fish and Wildlife Service The United States Fish and Wildlife Service (USFWS or FWS) is an agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats. The mission of the agency is "working with othe ...

lists the population status as "declining."

Habitat

The woundfin tolerates highly mineralized, turbid waters. It is typically found in warm, swift streams of high

turbidity Turbidity is the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality. Fluids ...

, preferring a stream speed of one to two feet per second and a depth of eight to eighteen inches. Woundfin lives in part of salty streams, avoiding clear waters and rarely can be found in quieter pools.

Food

The woundfin is

omnivorous An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nut ...

, and depending on availability will feed on detritus,

alga Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...

s, and aquatic

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three ...

s and their

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. ...

e."''Plagopterus argentissimus''
"

NatureServe NatureServe, Inc. is a non-profit organization based in Arlington County, Virginia, US, that provides proprietary wildlife conservation-related data, tools, and services to private and government clients, partner organizations, and the public. Nat ...

. June 9, 2006 version. Retrieved on July 16, 2006.

Conservation status

Historically, the woundfin also occupied the lower

from the Virgin to

Yuma, Arizona Yuma ( coc, Yuum) is a city in and the county seat of Yuma County, Arizona, United States. The city's population was 93,064 at the 2010 census, up from the 2000 census population of 77,515. Yuma is the principal city of the Yuma, Arizona, M ...

, and the Gila River from Yuma to its confluence with the Salt River, but

through water development (including eight major dams which alter flow) and the

introduction Introduction, The Introduction, Intro, or The Intro may refer to: General use * Introduction (music), an opening section of a piece of music * Introduction (writing), a beginning section to a book, article or essay which states its purpose and g ...

of several species (particularly the

(''Cyprinella lutrensis''), which competes for food and is known to prey upon the woundfin's eggs and young"''Designation of Critical Habitat for the Woundfin and Virgin River Chub''
" Federal Register. January 26, 2006 edition.. Retrieved on July 23, 2006.) have led to its

in these regions as well as a decline in population in the Virgin River. Since 1970, the woundfin has been listed as an endangered species. Other listings include "Vulnerable" on the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...

and "Critically Imperiled" (the most critical classification) by

. The

lists the population status as "declining." The Dexter National Fish Hatchery in

Dexter, New Mexico Dexter is a town in Chaves County, New Mexico. The population was 1,266 at the time of the 2010 census. Geography Dexter is located in south-central Chaves County at (33.196062, -104.370222), approximately west of the Pecos River. New Mexico St ...

studies the woundfin in an effort to help conserve the species, and has successfully spawned the fish in captivity. However, efforts to transplant the species into other rivers and creeks have failed due to reproduction not taking place.Endangered Species Protection Program

United States Environmental Protection Agency The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it ...

. Updated May 2, 2006. Retrieved on July 16, 2006. On July 11, 2007, approximately 50 woundfin were released into the Hassayampa River near Wickenburg, Arizona. The hatchery-raised fish were from wild Virgin River stock. The only wild population of the species is in the Virgin River. An aggressive program to eradicate red shiner from the Virgin River in Utah has all but removed red shiner from reaches previously dominated by red shiner. Fish barriers have been erected to prevent re-colonization by red shiner, and has allowed the reintroduction of hatchery raised woundfin. Several thousand of hatchery-raised woundfin were released in the fall of 2007 and 2008. With red shiner no longer a threat, low flows and high temperatures are the biggest threats still facing woundfin. Another minnow, the

Virgin River chub The Virgin chub or the Virgin River chub (''Gila seminuda'') is a medium-sized, silvery minnow, generally less than 15 cm long and reaching lengths of 25 cm. The back, breast, and part of the belly are embedded with small scales, naked ...

(''Gila seminuda''), has much of the same range as the woundfin and thus faces the same threats of extinction, particularly competition from the red shiner and a decrease in water quality as the result of agricultural runoff.

References

* * {{Taxonbar, from=Q2630710 Leuciscinae Fish of the Western United States Monotypic fish genera Fish described in 1874 Critically endangered fauna of the United States