Woundfin

Plagopterus argentissimus

SPECIES CODE: E00Z V01

STATUS:

Listed Endangered on October 13, 1970 (35 FR 16047 16048), Critical Habitat listed on January 26, 2000 (65 FR 4140 4156). Recovery Plan approved on April 19, 1995.

Note: All descriptions are abstracted or excerpted from the Recovery Plan (1994), and the Federal Register (2000).

SPECIES DESCRIPTION:

Woundfin is a member of the Cyprinidae family. The woundfin is considered the most highly specialized species in the genus Plagopterini (Miller and Hubbs 1960). The species rarely achieves a standard length of more than 7.5 cm (3in). Woundfin are opportunistic omnivores, and will feed on filamentous algae, detrital material, tamarisk seeds, and insects depending on availability.

REPRODUCTION AND DEVELOPMENT:

Seasonal rains and increased flows from snow melt runoff induce spawning, and spawning takes place during the period of declining spring flows. The spawning period is from April to July.

RANGE AND POPULATION LEVEL:

Historically, the woundfin occurred from near the junction of the Salt and Verde Rivers at Tempe, Arizona, to the mouth of the Gila River at Yuma, Arizona (Gilbert and Scofield 1989; Minckley 1973). Woundfin were also found in the mainstem Colorado River from Yuma (Jordan and Everman 1896; Meek 1904; Follett 1961) upstream to the Virgin River in Nevada, Arizona, and Utah and into La Verkin Creek, a tributary of the Virgin River in Utah (Gilbert and Scofield 1898; Snyder 1915; Miller and Hubbs 1960; Cross 1975).

Except for the mainstem of the Virgin River, woundfin are extirpated from most of their historical range. Woundfin presently range from Pah Tempe Springs (also called La Verkin Springs) on the mainstem of the Virgin River and the lower portion of La Verkin Creek in Utah, downstream to Lake Mead.

HABITAT:

Adult and juvenile woundfin inhabit runs and quiet waters adjacent to riffles with sand and sand/gravel substrates. Adults are generally found inhabits with water depths between 0.15 and 0.43 meters (m) (0.5 and 1.4 feet (ft)) with velocities between 0.24 and 0.49 meters per second (m/s) (0.8 and 1.6 ft/s). Juveniles select areas with slower and deeper water, while larvae are found in backwaters and stream margins which are often associated with growths of filamentous algae.

PAST THREATS:

The decline of the species is attributed to habitat loss and modification, and competition from introduced exotic fish species. Building of dams and associated reservoirs, water diversion structures, canals, laterals, aqueducts, and the dewatering of streams cause loss or degradation of available habitat. There are 10 known introduced fish species, however, the red shiner (Cyprinella lutrensis) and the black bullhead (Ameiurus melas) are the most abundant. Red shiners compete with woundfin for food and habitat, and possibly feed on woundfin larvae. Other predators on woundfin include piscivorous birds such as kingfishers and herons, soft-shelled turtles and other vertebrate species.

CURRENT THREATS:

The species continues to be threatened by habitat loss and modification, as well as competition from introduced nonnative fish, and predation.

CONSERVATION MEASURES:

LITERATURE CITED:

U.S. Fish and Wildlife Service. 1994. Virgin River Fishes Recovery Plan. Salt Lake City, Utah. 45pp.