Tiny Fish Threatened by Brewing Water War : Environment: The Devil’s Hole pupfish clings to life in what may be the most restricted environment in the world in the Nevada desert.

An ancient species of tiny fish survives in the arid Nevada desert in possibly the most restricted environment on Earth--the upper waters of fathomless Devil’s Hole.

The hole, a grave for curious scuba divers and a labyrinth of water-filled caverns, is the home of Cyprinodon diabolis wales-- or the Devil’s Hole pupfish.

The endangered fish was saved in 1976 by a Supreme Court opinion that blocked the pumping of underground water by nearby ranchers. But survival of the pupfish may once again be jeopardized by a brewing water war.

The tiny creatures spawn and feed on a special algae found on a natural ledge covered by only a few inches of water. “If the water level drops for any reason, they will die,” said David Buck, supervising biologist for the Nevada wildlife department.

Nevada’s populous Clark County--home to the gambling capital of Las Vegas--is seeking rights to 865,000 acre-feet of water held in rocks deep beneath three rural counties. Clark County claims it needs the water to support its growth booms, but the rural counties oppose the move.

The endangered pupfish may wind up in the middle of the fight, which again will undoubtedly be won or lost in the courts.

The dark-colored fish, which turns blue when sexually mature, clings to a precarious life on the spawning ledges of Devil’s Hole, a 40-acre site that was made part of Death Valley National Monument in 1952.

Steve Bradhurst, a planning consultant for Nye County, one of the counties above the contested water, says a new federal report implies that the fragile home of the Devil’s Hole pupfish could be damaged by thirsty Clark County, where per-capita water consumption is among the highest in the nation.

The report, by the U.S. Geological Survey, shows that water flowing into Devil’s Hole originates in rural eastern and central Nevada--the same place from which the Las Vegas Valley Water District wants to export water through a proposed $1.5-billion aqueduct system.

“Sustained withdrawal of water from the carbonate-rock aquifers would entail . . . capturing some water that would otherwise discharge from the Ash Meadows, Muddy River and Death Valley areas,” said the government survey, referring to the area of Devil’s Hole.

Devil’s Hole has never been fully explored. No one has found the bottom. And besides the pupfish, no creatures other than snails and a flat worm are known to live in its 90- to 100-degree waters.

The strange limestone sinkhole was left behind when Pleistocene Age lakes that once covered parts of the Nevada desert receded 50,000 to 500,000 years ago. Devil’s Hole is located at a higher elevation than other desert pools, indicating it may have been isolated first.

Researchers say the Devil’s Hole pupfish, about three-quarters of an inch long when mature, probably established its home in the foreboding environment at least 10,000 years ago--more than 5,000 years before Egyptian Pharaohs built pyramids along the Nile.

“There is discussion now as to whether the Devil’s Hole pupfish is the oldest of all pupfish and perhaps has been isolated the longest,” Buck said.

At least a dozen other species of pupfish exist in warm springs throughout the arid Southwest--each species adapting to its environment and developing special characteristics required for survival.

“If Charles Darwin had known of them, he would have been enthralled, for they are among the world’s best examples of divergent evolution, as remarkable as the Galapagos finches which inspired him to form his theory of evolution,” conservationist Sterling Bunnell wrote.

Some pupfish have lived in waters ranging from freezing to above 100 degrees. They have adjusted to salt concentrations up to six times that of seawater. But the Devil’s Hole pupfish enjoy clear, warm waters fed by an unmapped source.

The desolate area has an aura of superstition and mystery.

According to Indian legend, a maiden once fell into Devil’s Hole and her body was found days later in a Death Valley spring, miles away. Storytellers say her body was carried by currents of the underground Amargosa River from cavern to cavern until it surfaced in a desert pool.

But when two young divers tried to explore Devil’s Hole 25 years ago, they disappeared.

Pupfish are capable of darting back and forth in their restricted environment in spurts of one foot per second. Their domain extends from the small mouth of Devil’s Hole to a depth of about 90 feet. Below that, the maze of waterways balloons into giant caverns and is totally dark.

Depending on the season, only 250 to 500 of the Devil’s Hole pupfish live near the entrance to their mysterious confines. They live and die in a pool of warm water with a 10-foot opening at the surface.

A monument built inside the fence guarding the entrance to Devil’s Hole reads:

“In the small pool at the bottom of this limestone cavern lives the entire population of Cyprinodon diabolis , one type of desert pupfish. These fish live in what is probably the most restricted environment of any animal in the world.”