In the 1970s, it was not uncommon to spot cars around Nye County, Nevada, sporting stickers that said “Kill the Pupfish.”
These were made in response to stickers saying “Save the Pupfish,” which had been distributed by the Desert Fishes Council—a key player involved in the preservation of the Devils Hole pupfish, the world’s rarest fish.
The Supreme Court had been presiding over a case which would decide whether the pupfish’s sole habitat could be exploited for irrigation. This landmark case would go on to decide the fate of the smallest pupfish in existence—numbering around 300 at the time and at serious risk of extinction.
But what made the Devils Hole pupfish, a fish that measures no longer than an inch, such a contentious creature? Here’s the story of this little fish that continues to weather the forces of nature, humanity and even a drunk trespasser’s briefs.
The Devils Hole Pupfish Is Locked In A Battle Against All Odds
The habitat housing the Devils Hole pupfish (Cyprinodon diabolis) is as aptly named as it gets. Death Valley National Park, where the Devils Hole is located, is the hottest and driest national park in the United States.
In the waters of Devils Hole, the temperature remains a warm 92 °F through the year. The oxygen levels, however, remain incredibly low. Yet, the pupfish has evolved an extraordinary survival mechanism—it stops breathing. And it can keep this going for up to two hours at a time.
When oxygen levels plummet, this tiny fish can halt aerobic respiration and switch to a process known as “paradoxical anaerobism.” This metabolic state enables the pupfish to produce energy without oxygen, with ethanol as a byproduct—a feat most vertebrates would find toxic. By embracing this unique strategy, the Devils Hole pupfish defies conditions that would otherwise spell certain death.
Compounding these challenges is the highly variable availability of nutrients that fuel the ecosystem’s food web. Seasonal fluctuations in nutrient input can directly affect the algae and invertebrates that sustain the pupfish. With its living quarters confined to a virtual species-sized “fishbowl,” any disruption carries an outsized impact, leaving no room for escape or recovery.
Despite the complex web of challenges circling in on the Devils Hole pupfish, this determined little creature finds a way to defy all expectation—and in the most unconventional means imaginable. In fact, only 35 pupfish remained in the the world in 2013, although numbers have picked up since.
It Thrives On Seismic Aphrodisiacs, Owl Droppings and Chaos
You might think a fish that can stop breathing to survive has adapted enough already, but hold your breath.
While most creatures would quiver at the thought (and the force) of an earthquake, the Devils Hole pupfish seizes the opportunity to spawn, even out of season. As soon as the earth starts to shake, the pupfish dive to the depths of Devils Hole, with each male chasing a female pupfish to procreate as soon as physically possible.
Flash floods, too, serve as an unexpected boon.
Although these sudden torrents initially wash sediment and debris into Devils Hole, smothering eggs and reducing water depth, they eventually deliver a surge of nutrients into the ecosystem. Over time, algae and diatoms flourish, forming a richer food base that rejuvenates the pupfish population.
Adding to this nutrient influx are barn owl pellets, an unlikely ally for the pupfish. When barn owls drop their nutrient-rich waste into the water, it stimulates microbial and algal growth, directly enhancing the food web. These pellets—brimming with organic material from undigested prey—support a thriving ecosystem where algae, invertebrates and pupfish coexist.
For a species living on the edge, these peculiar contributions from nature prove to be lifelines, sustaining their existence against all odds.
From Supreme Court Rulings To Drunk Trespassers, The Pupfish Has Seen It All
If the environmental threats to the Devils Hole pupfish weren’t enough, humanity has thrown its fair share of challenges at this defiant little fish that continues to maintain its meager numbers.
Efforts to conserve the Devils Hole pupfish began in 1952, when Devils Hole was made a part of the Death Valley National Park and the species was the first to be considered endangered under the Endangered Species Act in 1967.
Despite these efforts, not everyone loved the little pupfish.
From 1967 to 1970, landowners in Ash Meadows began to drill wells for irrigation, leading to a depletion of the water level at Devils Hole. Recognizing the threat to the continued existence of the pupfish, the federal government initiated proceedings to halt the drawing of water from this region.
This would culminate in the case Cappaert v. United States, where the Supreme Court ruled that pumping of water must be limited to maintain sufficient groundwater levels around Devils Hole to protect the pupfish from extinction. But that was hardly the end of the pupfish’s struggles.
In 2016, three trespassers broke into Devils Hole, vandalised equipment installed to monitor the pupfish and vomited in the protected waters. One of them even left their boxers behind. Fortunately, the damage to the population was minimal, with one fish turning up dead from a population then numbering 115.
Today, Conservation Efforts Continue To Make An Impact
The survival of the Devils Hole pupfish hinges on meticulous conservation efforts that span decades and involve a blend of legal protection and habitat management.
Following the Supreme Court decision to secure groundwater levels, the focus shifted to maintaining the fragile Devils Hole ecosystem. In 1980, the U.S. Fish and Wildlife Service (USFWS) designated 21,000 acres as critical habitat to protect the aquifer feeding Devils Hole. This safeguard ensured a consistent water source but did not address other challenges like nutrient fluctuations and malnourishment.
A turning point came with the establishment of the Ash Meadows National Wildlife Refuge in 1984. In recent years, the Ash Meadows Fish Conservation Facility has built a high-tech replica of Devils Hole, complete with precise water chemistry and sunlight. This refuge offers a backup population of pupfish, maintained through egg transfers and stringent health protocols. The captive population has been vital in bolstering numbers, especially during population lows.
Today, the wild population of the Devils Hole pupfish has climbed to 263 as of August 2024, marking a cautious yet remarkable success for one of the world’s rarest fish. However, with threats still looming, the pupfish remains a symbol of the delicate balance between nature and human intervention.
While the Devils Hole pupfish has endured it all over the years, human actions and climate change continue to threaten its existence. Does the constant threat of climate change cloud your mood? Take this 2-minute quiz to see where you stand on the Climate Change Worry Scale.
