Death Valley pupfish

The spring-fed pools of upper Salt Creek are the year-round habitat of pupfish

The desert pupfish is a small, silvery colored fish with 6–9 dark bands on its sides. It has an average length of 3.7 cm (1.5 in), with a recorded maximum of 7.8 cm (3.1 in).[2]

The males turn bright blue during mating season, April through October. The pupfish can withstand harsh conditions that would kill other fish: water that is 4 times more saline than the ocean, hot water up to 116 °F (47 °C), and cold water down to 32 °F (0 °C).[3]

This species is known from only two locations in Death Valley: Salt Creek (subspecies salinus) at about 49 m (161 ft) below sea level, and Cottonball Marsh (subspecies milleri), at about 80 m (260 ft) below sea level.[1] They are thought to be the remainders of a large ecosystem of fish species that lived in Lake Manly, which dried up at the end of the last ice age leaving the present-day Death Valley.[4]

The Salt Creek subspecies is also found at River Springs and Soda Lake, in Death Valley National Park.[3]

The desert pupfish has been classified as endangered by the IUCN because of its extremely restricted distribution (if the two extant locations were treated as a single unit, it would be considered critically endangered). Numbers of individuals at the locations are highly seasonally variable, and fluctuate with water level and flow volume. While the entire range of the species is located in a protected area, it may be under threat from accidental introduction of non-native species, local catastrophic events, and excessive pumping of the aquifer that feeds the habitat.[1]

• Tecopa Pupfish, Cyprinodon nevadensis calidae (extinct)
• Saratoga pupfish, Cyprinodon nevadensis nevadensis, from Saratoga Springs at the south end of Death Valley
• Amargosa pupfish, Cyprinodon nevadensis amargosa, from the Amargosa River northwest of Saratoga Springs
• Devil's Hole pupfish, Cyprinodon diabolis, critically endangered and found in Devil's Hole, in western Nevada
• Shoshone Pupfish, Cyprinodon nevadensis shoshone
• Desert pupfish Cyprinodon macularius
• Owens pupfish Cyprinodon radiosus

• Duvernell, D. D.; Turner, B. J. (1999). "Variation and divergence of Death Valley pupfish populations at retrotransposon-defined loci" (PDF). Molecular Biology and Evolution. 16 (3): 363–371. doi:10.1093/oxfordjournals.molbev.a026117.
• Lema, S. C. (2008). "The phenotypic plasticity of Death Valley's pupfish: desert fish are revealing how the environment alters development to modify body shape and behavior". American Scientist. 96 (1): 28. doi:10.1511/2008.69.3668.
• Jahren, A. H.; Sanford, K. L. (2002). "Ground-water is the ultimate source of the Salt Creek pupfish habitat, Death Valley, U.S.A" (PDF). Journal of Arid Environments. 51 (3): 401–411. Bibcode:2002JArEn..51..401J. doi:10.1006/jare.2001.0950.

• Media related to Cyprinodon salinus at Wikimedia Commons
• "Cyprinodon salinus". Integrated Taxonomic Information System. Retrieved 18 January 2014.