A member of the Cyprinidae family and the sole species in the genus Moapa, the Moapa dace lives only in the warm springs of the upper Muddy River and has a distinctive leathery appearance — hence the scientific name coriacea , which means “leathery.” When first discovered in 1938, the dace was considered common, with a 10-mile range including 25 thermal springs. Today its habitat is limited to three springs and a less-than two-mile stretch of the Muddy River. Surveys in 2008 found only 460 dace remaining; thanks to a fire that decimated the Warm Springs Oasis in summer 2010, the fish's survival hangs in the balance.


Because of the threats of development, groundwater pumping and nonnative species, the Moapa dace gained endangered status in 1967 and earned a recovery plan in 1983. Unfortunately, the plan's protections haven't been adequately implemented, while threats continue — and some loom larger than ever. Though the recovery plan called for habitat restoration and estimated at least 6,000 adult Moapa dace would be needed for long-term survival, federal agencies continue to approve plans to develop and mine the ancient groundwater carbonate aquifers that provide water to dace's warm-spring and Muddy River home.

Projects like the Coyote Springs Master Planned Development of Lincoln and Clark counties and the southeastern Lincoln County planned developments, as well as the rapid pace of development along the lower Muddy River and the Virgin River, are placing seriously unsustainable demands upon the carbonate aquifers the dace needs. Worsening matters, the Southern Nevada Water Authority plans to develop and mine more than 200,000 acre-feet from the aquifers, which will reduce the area's water table, alter water temperatures and chemistry, change habitat structures and reduce water flow — perhaps eliminating it altogether.


The Center is actively opposing the water developments and other threats to Moapa dace and their habitat. In August 2010 we sued the Interior Department for allowing the Southern Nevada Water Authority to place the Moapa dace in jeopardy. Earlier that year we filed 130 protests against water-rights applications that posed a threat to the dace and other Nevada species.

In 2020 we filed a lawsuit against the Nevada state engineer for allowing groundwater pumping that reduces spring flows and endangers this rare fish.


Photo courtesy USFWS