Woundfin  (Plagopterus argentissimus)

The woundfin is classified as Vulnerable (VU) on the IUCN Red List (1) and is listed on Appendix II of CITES (3).

Described as the most silvery-coloured of the American Cyprinidae family, the woundfin (Plagopterus argentissimus) is a small, streamlined minnow native to just a few river systems in North America (2). This slender fish can easily be identified by its flattened head and body, large, curved fins and barbels (4). It also lacks scales and has a sharpened spine on its dorsal fin (2).

The woundfin is native to North America, where its range originally encompassed the Colorado River basin, including the Virgin, Moapa, Salt and Gila river systems (4). It is now believed to be restricted to the Virgin River in the states of Utah, Arizona and Nevada (4).

This species is commonly found in warm, swift-flowing and highly turbid streams with a constantly shifting sand and gravel substrate (2) (4). The woundfin prefers shallow stream depths of around 20 to 46 centimetres, and can be found at elevations from 580 to 3,050 metres (4). The young of this species inhabit quieter backwaters with sandy substrates (4).

Being omnivorous, the woundfin has a varied diet and is known to feed on algae, seeds and detritus, as well as aquatic insects and their larvae (4) (5).

The woundfin reproduces throughout the summer from around April or May, until August (2). Spawning takes place over a substrate of small stones, preferably in an area with a current. The eggs are adhesive and stick to the underside of small rocks, where they take around 10 to 11 days to develop (6). The young woundfin, or fry, mature in their second summer, and individuals are believed to live for up to four years (4).

From being the most abundant species in the Virgin River, the woundfin has suffered a dramatic population decline (2). Loss and fragmentation of its habitat due to human activities is thought to be a major contributing factor in this decline (1) (4). The damming of the rivers and use of the water for agriculture and mining have also led to changes in the flow regimes of the rivers in the woundfin’s range (2) (4).

Another major threat to the woundfin is the introduction of the non-native red shiner (Cyprinella lutrensis) (4). This species has replaced the woundfin through much of its original range and has also introduced the Asian tapeworm (Bothriocephalus acheilognathi), which is having a detrimental affect on the remaining woundfin population (2) (7).

A major priority for the conservation of the woundfin is the protection and monitoring of its remaining habitat (4). Research is also being carried out in order to refine captive breeding methods so that this species can be re-introduced back into its historic range. However, previous attempts to reintroduce the woundfin have proved unsuccessful (4).

Further recommended measures to conserve the woundfin include the restoration of the flow regime in its native rivers and the eradication of non-native species such as the red shiner (2). The woundfin is also listed on Appendix II of the Convention on International Trade in Endangered Species (CITES), meaning that any international trade in this species should be carefully regulated.

Find out more about the conservation of the woundfin and other North American species:

• Fishbase:
  http://www.fishbase.org/summary/Plagopterus-argentissimus.html
• United States Environmental Protection Agency:
  http://www.epa.gov/
• Arizona Game and Fish Department:
  http://www.azgfd.gov/