The Earth has undergone an extremely long process of evolution, and its environmental conditions are unpredictable and not always as habitable as they are now. Life born on the earth can only adapt to the environment, and if you want to survive, no matter how harsh the conditions, you must grit your teeth and insist.
Nature follows the basic law of "natural selection, survival of the fittest", and those species that fail to resist external pressures and adapt to the environment cannot continue to reproduce. In the history of Earth's evolution, there have been about five large-scale species extinctions, and those who remain through screening will only evolve stronger and more adapt to the new living environment.
Humanity is constantly evolving
However, in the process of earth's change, an unexpected "variable" appears, that is, human beings. Humans have used their wisdom to develop technology, create societies and civilizations, and climb to the top of the natural food chain. In the process of development and progress, human beings have inevitably had a major impact on the natural environment and compressed the living space of other species.
Extinction is normal, but human influences have greatly exacerbated the process and number of extinctions of some species. Environmental pollution, habitat destruction, hunting and killing... Many animals that once had a long history of existence on Earth and a huge number of advantages have become endangered species.
Today we will talk about a very representative endangered species, they are a fish living in the desert, with a history of at least 50,000 years, now there are only 38 left, and almost because of human negligence directly "annihilated". What kind of hardships have led them to such a situation?
Medaka
<h1 class="pgc-h-arrow-right" data-track="6" > isolated from the world and surviving in the cracks</h1>
Devil's Hole pupfish, also known as "desert fish" and "manta rays", sounds very domineering, but in fact, they are petite, the scales of the whole body show a bright dark blue luster, the appearance is beautiful and harmless, and it is definitely not as oppressive as the name.
Tiny and tenacious life
As the smallest species of the medaka genus , they do not exceed 30 mm in length and have an average length of only 23 mm. A distinguishing feature that distinguishes males from females is the color, the males are dark brown overall, the edges of the fins are black, with a little gold on the back, and the gills have a violet luster, showing a beautiful metallic blue in the light.
Male medaka
Females and juveniles are yellowish in color and have a yellowish-brown back. The head is large but not a ventral fin , the scales on the outer edge are ctenophoric or toothed , and the male has a black streak on the caudal fin.
The origin of the medaka is controversial, with the species widely believed to have been born about 60,000 years ago, but some researchers believe it has existed only as an independent species for 10,000 to 20,000 years. It was not until 1930 that the medaka was introduced by the American ichthyologist Joseph M. Thompson. H. Wales is defined as a new species and has entered the public eye.
Female medaka
Obviously, this is a tiny creature that is inconspicuous, but it is deeply rooted in the desert of the United States, isolated from the world, and tenaciously survived from generation to generation, known as the "miracle of evolution".
The worst place is the only habitat
The reason why the medaka is difficult to find is that its living environment is quite harsh, almost an isolated and desolate land. In the U.S. state of Nevada, there is a desert known as the "Valley of Death", which has an underground aquifer called the "Devil's Cave", which is also the origin of the name of the medaka.
"Valley of Death"
The "Valley of Death" desert in Nevada, USA, is known for its extremes and droughts, high temperatures, summer temperatures can usually reach 50 ° C, in extremely dry periods, the humidity in this area can be said to be close to zero.
Devil's Cave is an oasis in the Valley of Death, which is part of an extensive groundwater system. About 6,000 years ago, a narrow crack appeared in the Amagosa Valley, where melted snow or rain seeped into the ground, and together with the release of water flow deep underground, eventually formed an underground aquifer.
Although a precious source of water in the desert, the water temperatures in the local waters of Devil's Cave can reach a maximum of 92 °C, and the average water temperature is maintained at around 32 °C, which makes it sound more like a hot spring than a groundwater cave, a climate that is not suitable for any fish to survive and thrive here.
Devil's Hole is known as the "Devil's Flush Toilet"
What made the medaka come here and evolve on its own for tens of thousands of years? Scientists speculate after research that during the Ice Age, the "Devil's Valley" was also a water system, through underground tunnels, flood disasters and other reasons, several desert fish separated from their populations and trapped in the "Devil's Cave".
Isolated from the world in this extreme environment, they evolved for 50,000 years, eventually giving birth to a new, tiny species. The timing of the medaka's origin is controversial because of differences in the timing and reasons for the separation of this unique subpopulation from the original desert fish population.
The scientists have proposed a new hypothesis that the fish were likely brought here by accident by humans or birds, rather than being influenced by natural forces. Although their origins are full of controversy, it is certain that the "Devil's Valley", which has such a harsh environment, is the habitat of the medaka generation, and this small, small pond with a total area of about tens of square meters is the only home on which they depend.
Critically endangered
However, such a "no-fight" and "survival- demon medaka" is about to lose their only habitat. The medaka, which did not lose to the harsh environment such as high temperature, lack of oxygen, and lack of food, was deeply threatened by humans. Beginning in the 1970s, Americans pumped groundwater aggressively to irrigate farmland, leading to the depletion of groundwater resources in the region.
The reproductive ability of the medaka itself is extremely low, and during each spawning period, the mature female only lays a fish egg with a diameter of about 1 mm, and the hatching success rate of the eggs is not high. Affected by the harsh environment, the survival rate of juvenile fish is worrying, and the individual lifespan is only 10 to 14 months.
Females generally lay their eggs on the shallow continental shelf, but are limited by a sharp drop in water levels, resulting in a continuous decline in the breeding capacity of the medaka. In addition to the threat of groundwater depletion due to agricultural irrigation, inbreeding, food shortages, changes in algae and microbial communities, earthquake disasters, etc. are all potential factors contributing to its decline.
In the early 1990s, the number of medaka in the "Valley of Death" desert plummeted to more than 500. By 2006, when researchers counted the number, they searched the entire desert and found only 38 of them! They may well have become the most endangered fish in the world. What is even more painful is that the only remaining 38 magic medaka have been directly affected by human behavior and have almost been "served in one pot".
<h1 class="pgc-h-arrow-right" data-track="26" > drunks trespassing in the "Devil's Hole" to cause jail time</h1>
In order to protect the endangered medaka, the United States has set up a special nature reserve in the "Devil's Cave", which is isolated by a fence to create a solid "fortress" to guard the medaka. But all the tranquility was shattered in April 2016 when three young men descended to Nevada's "Valley of Death" desert to camp carefree on empty nights and pick up guns to make it the ideal hunting ground.
Three young men named Trent, Steven and Edgar left the camp in a buggy drinking rum accompanied by gunfire. As they crossed the Amagosa Valley and the Ash Meadows National Wildlife Refuge, they picked up shotguns and fired at road signs.
Alcohol-on-head behavior is uncontrolled
Soon, drunk, they arrive at a remote reserve in Death Valley National Park: The Devil's Cave, where the three realize it is a deep pool of water located inside a sunken limestone cave. Because they were drunk, their courage grew, and they planned to break into the underground water pool to find out.
Dodging surveillance cameras, the three stumbled across the fence, destroying protective equipment and wading into the shallow devil's hole. Steven was thoroughly drunk and began to understand in his confusion. His companion Trent wanted to play a prank and waved his fist at him, causing Steven to hurry up to a large rock and vomit into the water. Trent dropped his shotgun, stripped off his clothes, and dived into the deep, warm waters of the Devil's Hole to swim.
Devil's Hole
The three "drunks" were completely unaware that their actions had seriously threatened the survival of the medaka, directly leading to the death of one medaka and the destruction of countless fish eggs. This would be the worst mistake they made that night, nearly leading to the extinction of a rare and endangered species.
The court eventually convicted the three of them of violating the Endangered Species Act and damaging federal property, and were detained for a year by the Federal Prison Service, paying nearly $14,000 in damages and a $1,000 fine to the National Park Service. Since then, the Park Authority has stepped up protection against the Devil's Hole, adding an additional ring of barbed wire to cover the towering fence. More cameras, sensors and "no unauthorized intrusion" warning signs were placed around the area.
Devil's Cave is fenced
<h1 class="pgc-h-arrow-right" data-track="33" > From Fear to Hope: The Journey to Save the Medaka</h1>
Realizing that the medaka's situation was precarious, the United States took some protective measures against the authorities in an attempt to save this tenacious species from disappearing from the earth completely. As early as 1967, the medaka was defined as an endangered species, becoming one of the first species protected by the Endangered Species Act, and its degree of attention is self-evident.
Local researchers have made a lot of efforts to help the medaka rejuvenate, such as setting up a special research team to monitor and investigate its ecological environment, and trying to artificially breed medaka in the laboratory. In addition, the federal government has banned nearby farmers from using groundwater to irrigate their farmland, thereby restoring and stabilizing the groundwater level in the Devil's Cave and protecting their only habitat.
The "Devil's Cave" is also classified as part of the National Monument, thus increasing the publicity for the protection of the medaka and attracting the attention of people from all walks of life.
Add protection to devil's holes
For more than 40 years, people have been working hard to protect the medaka, and these efforts have not been wasted, and the current survival status of the medaka has improved. The staff of "Devil's Cave" said that in the laboratory, about 10 to 20 medaka have matured through artificial breeding and breeding, and have begun to lay eggs. In 2018, the number of medaka has increased to 187, which also gives people hope to restore the vitality of the medaka population.
<h1 class="pgc-h-arrow-right" data-track="38" > conclusion</h1>
One might ask, why bother to protect such an inconspicuous tiny species? What is the significance of maintaining biodiversity? The answer is simple, because man and nature themselves are an inseparable whole, and we should live in harmony with nature, rather than blindly and selfishly pursuing economic and civilizational development.
The green water and green mountains are the golden mountains and silver mountains
The cost of human destruction of nature is tragic, as long as human beings still share an earth with other species, the evil consequences of those sown will sooner or later fall on their own heads. To protect biodiversity is to protect human beings themselves.
We have sacrificed so many animal habitats that endangered natural creatures should not have been left to it. Therefore, while it is not too late, human beings should return to their authenticity, while promoting their own development, they must also pay attention to protecting the ecological environment and find a way to live in harmony with nature.