Eremichthys acros

Desert dace

Family: Unknown · Class: Actinopterygii · Order: Unknown

Conservation status: Threatened

The desert dace is a small olive green and silver fish endemic to thermal springs in northern Nevada. Adults typically measure 50 to 70 mm (2.0 to 2.8 inches) in total length, with a streamlined body adapted for life in warm water environments. The species exhibits the distinctive minnow body form with a terminal mouth and relatively large eyes. Coloration consists of olive-green dorsal surfaces transitioning to silver sides, providing camouflage against the substrate of thermal springs. Desert dace occur exclusively in several thermal springs and their outflows within Soldier Meadows, located in northwestern Humboldt County, Nevada. The species' range is extremely restricted, confined to a few interconnected spring systems within this geothermal area. Historically, the distribution may have been slightly broader within the Soldier Meadows complex, but habitat modifications have reduced available habitat. The species inhabits thermal springs and associated outflow channels where water temperatures remain elevated year-round. Desert dace demonstrate the highest temperature tolerance of any minnow species in western North America, surviving in waters reaching 40°C (104°F) (USFWS 2025). This extreme thermal tolerance allows the species to exploit a unique ecological niche unavailable to other native fish species. The springs typically maintain stable temperatures and flow rates, creating consistent habitat conditions essential for the species' survival. Desert dace exhibit behavioral adaptations to their thermal environment, including the ability to move between areas of varying temperature within the spring systems to optimize physiological conditions. The species feeds opportunistically on small invertebrates, algae, and organic matter available within the spring ecosystems. Reproductive biology remains poorly documented, though spawning likely occurs multiple times per year given the stable thermal conditions. Juveniles and adults occupy similar habitats within the spring systems. Desert dace was listed as threatened under the Endangered Species Act on March 11, 1967, making it one of the first fish species to receive federal protection. The primary threat to the species is habitat modification associated with agricultural development and irrigation diversions that alter spring flows and temperatures (USFWS 2025). Water extraction for agricultural purposes can reduce spring discharge, potentially concentrating fish in smaller areas and making populations more vulnerable to environmental fluctuations. Additional threats include potential groundwater pumping that could affect spring flows and possible introduction of non-native species. Recovery efforts have focused on habitat protection and monitoring population trends within the limited range. The species' recovery plan was finalized in 1997, establishing conservation measures and research priorities (USFWS 2025). Population monitoring indicates the species remains present in its known locations, though detailed population estimates are limited due to the challenging sampling conditions in thermal springs. The extremely restricted range makes desert dace particularly vulnerable to any habitat disturbances, emphasizing the importance of continued protection of the Soldier Meadows spring systems.

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, and more.