Crenichthys baileyi

Small range in spring systems in the White River system, Nevada; threatened by habitat degradation and interactions with introduced fishes.

Range is confined to the pluvial White River system, southeastern Nevada, including springs of Moapa River (Lee et al. 1980, Deacon and Williams 1984, Page and Burr 2011).

Extent of occurrence is roughly a few hundred square kilometers (measured as a convex polygon that encompasses all populations).

Subspecies albivallis: spring remnants of uppermost White River drainage, White Pine County; occurs in Preston Big Spring, Indian Spring, Arnoldson Spring and Nicholas Spring, recently extirpated from Cold Spring and Lund Town Spring (Deacon and Williams 1984, Scoppettone and Rissler 2002).

Subspecies baileyi: spring pool of Ash Springs, Lincoln County.

Subspecies grandis: native to Crystal and Hiko springs, Lincoln County; introduced and established in Blue Link Spring in Mineral County, Nevada (see USFWS 1998).

Subspecies moapae: headwater springs of Moapa River, Clark County.

Subspecies thermophilus: Moorman and Moon River springs, and Hot Creek, Nye County (Minckley et al. 1991).

This species is represented by fewer than 20 extant occurrences.

Subspecies albivallis: when described in 1981, reported from 6 spring systems (Williams and Wilde 1981); found in only 4 spring systems in 1991 and in the late 1990s (Scoppettone and Rissler 2002).

Declines and extirpations have resulted from habitat alterations and interactions with introduced exotic fishes such as largemouth bass, convict cichlid (Cichlasoma nigrofasciatum), shortfin molly (Poecilia mexicana), sailfin molly(P. latipinna), and mosquitofish (Gambusia affinis) (Courtenay et al. 1985; see also Tippie et al. 1991). Introduced fish species continue to affect most populations.

Ash Springs is a population recreational area for swimming. This is not now believed to be highly detrimental to springfish, but in the past the pool was drained annually to remove algae, and this kept springfish populations low. Cessation of pool draining allowed the springfish population to increase (USFWS 1998). Non-native fish species continue to detrimentally affect the springfish population (USFWS 1998). Habitat changes associated with the presence of cattle resulted in increased mortality at Ash Springs (Taylor et al. 1989).

Hiko Spring population was extirpated in the 1960s after the outflow stream was modified for irrigation and non-native fish species were introduced. Springfish were reintroduced in 1984 and an increasing population was established (USFWS 1998)

Spring systems near the White River have been altered to irrigate pastures and hay crops (Scoppettone and Rissler 2002). A population of subspecies albivallis was extirpated from Lund Town Spring after the system was disconnected from other inhabited springs, possibly from chronic exposure to cooler water temperature (J. Deacon, pers. comm., cited by Scoppettone and Rissler 2002). Another extirpated population of albivallis at Cold Spring had only 10 meters of spring outflow available before the outflow entered a pipe; introduced guppies (predator on fish larvae) survive in Cold Spring (Scoppettone and Rissler 2002). A population of albivallis at Nicholas Spring showed little recent recruitment, possibly due to manipulation of spring flow for irrigation, which change the system from a pool to a shallow stream (may lead to drying of eggs) (Scoppettone and Rissler 2002).

American Fisheries Society (Jelks et al. 2008) listed four of the subspecies as Endangered and the other one as Threatened, due to (1) present or threatened destruction, modification, or reduction of habitat or range; (2) other natural or anthropogenic factors that affect existence, including impacts of nonindigenous organisms, hybridization, competition, and/or predation; (3) disease or parasitism; and/or (4) restricted range.