In the dead of night, mites begin to date and mate on your face | Nature Trumpet

In the past two weeks, we have collected the following natural research and news that you can't miss:

1) In the dead of night, mites secretly mate on your face

2) In Cambodia, the largest freshwater fish was discovered

3) In Australia, little blue penguins died en masse

4) In the United States, the largest female Burmese python was euthanized

5) Slender-horned gazelles are starving to death in Iraq

6) Four years ago, a mountain lion died in a car accident; four years later, its daughter and grandson also died.

Mites mating

Almost everyone has mites, living in our pores, feeding on skin debris and leading a pretty carefree life - no predators, no competition, and they even have sex at night!

Mites on human skin under a microscope - Demodex folliculorum | University of Reading

They only appear at night. Under the cover of darkness, the mites, which are only 0.3 mm long, crawl around on the surface of human skin, "seeing each other" on the spot, and the mites that are attracted to each other will begin to mate on the human hair all night. The strange thing is that the genitals of male mites grow on their backs, so they are located below the females during mating.

The male mite's genitals on the back (the Dorsal penis) | References [1]

Why do they only appear and mate at night? Can't they have sex during the day?

Recently, researchers have found the answer! The genome of mites has been streamlined during evolution, and many genes have been lost. As a result, they cannot be awakened by daylight, cannot be protected from UV damage, and cannot produce melatonin, which stimulates movement and mating behavior in mites. Although mites cannot produce melatonin, humans can! Every evening, they can "get free" melatonin secreted by humans and start a wonderful night life.

Although no one can see it clearly, the arrow is indeed pointing to the anus of the mite | University of Reading

The researchers also cleared a long-standing injustice for mites. It has always been believed that mites do not have an anus, and that the waste they accumulate will be released when they die, causing skin inflammation. This is not true! In fact, mites have a small anus that can be used to discharge waste on a daily basis. In addition, the presence of mites can also prevent the pores on our faces from being blocked.

largest freshwater fish

In Cambodia's Mekong River, local fishermen caught the largest freshwater fish in the world!

That's it! | Chhut Chheana/Wonders of the Mekong

It was a sand ray (Urogymnus polylepis), almost 4 meters long and weighing nearly 300 kilograms. After catching this big fish, the fishermen quickly contacted a nearby team of scientists responsible for conservation work. The scientists came overnight, recorded the big fish, installed a tracker on its tail, and then released the big fish back to the Mekong River with the fishermen. According to market prices, the fishermen also received $600 in compensation.

Local residents named this rare big fish "Full Moon" because its body is like a full moon. Moreover, when it was released, the moon appeared on the horizon.

Preparing to release the animals | Chhut Chheana/Wonders of the Mekong

The Mekong River flows through many countries and is home to many giant freshwater fish species. However, due to dam construction and overfishing, the number of the multi-scaled sand ray has decreased significantly and has been assessed as an endangered species by the International Union for Conservation of Nature (IUCN). Other giant freshwater fish are also facing the risk of extinction.

Scientists believe that the capture of this scaly sand ray not only set a new record, but also brought new hope to the ecosystem of the Mekong River. Including it, people have found four scaly sand rays in the past two months, and all of them are female. Scientists therefore speculate that there are spawning sites nearby, and hope to obtain more information about this species through trackers in the future.

Little blue penguin dies

More than 500 dead little blue penguins have washed up on beaches in New Zealand since May.

On different beaches, people have found corpses of several to dozens of little blue penguins. The largest number at one time was 183 little blue penguins washed up on the same beach - what killed them?

Little blue penguin | Magnus Kjaergaard / Wikimedia Commons

Experts found that the dead little blue penguins were significantly underweight. Little blue penguins are the smallest penguins in the world, and generally weigh 0.8 to 1 kilogram. But the dead little blue penguins weighed less than half of their normal weight and had almost no fat on their bodies. They probably died of starvation or hypothermia.

Due to the La Nina phenomenon, the ocean surface temperature rises, and fish enter deeper waters. Little blue penguins can only dive 20 to 30 meters deep and cannot eat fish deeper. Coupled with overfishing of fish, little blue penguins may not be able to find food.

Little blue penguin in water | Calistemon / Wikimedia Commons

This is not the first mass death of little blue penguins. Due to extreme climate, dozens or even hundreds of little blue penguins usually die every 10 years. But unfortunately, such tragedies are becoming more and more frequent, and have occurred three times in the past 10 years. If this tragedy cannot be curbed, the little blue penguin population may not be able to recover.

Catching Burmese Pythons

Recently, researchers in Florida, the United States, discovered the largest Burmese python ever found there. This female python is 5.4 meters long and weighs 97 kilograms, requiring several people to carry it.

Swipe left to view: Live photo of capturing python | Conservancy of Southwest Florid

Originally from Southeast Asia, the Burmese python was introduced to Florida in the 1970s and has since multiplied to become one of the most destructive invasive species in the region, preying on 24 mammals and 47 bird species, including the occasional alligator.

In order to reduce the number of Burmese pythons and protect the local ecosystem, experts have come up with many ways. Burmese pythons are difficult to detect in swamps and woodlands, so they implanted trackers into male pythons and released these "scout snakes" back into the wild to attract reproductively active female pythons. Female pythons can produce a large number of offspring at a time, and removing them can greatly reduce the damage to the ecosystem. The local government even launched a "Python Challenge", offering a bonus reward and calling on everyone to eliminate this invasive species.

Swipe left to view: Researchers found the last dinner of this python in its digestive tract｜The News-Press-USA TODAY NETWORK

The female python was found through the "snake scout" strategy. Researchers found 122 follicles in its abdomen, and fur, bones and hooves in its digestive tract, indicating that it had just had a full meal not long ago, eating an adult white-tailed deer. For the purpose of protecting the ecosystem, the Burmese python was euthanized.

Iraq's Slender-horned Gazelle

In just one month, the number of slender-horned gazelles in the Sawa reserve in southern Iraq dropped from 148 to 87.

Slender-horned Gazelle (Gazella leptoceros) | References [5]

The slender-horned gazelle lives in the desert, mainly in Iraq, Libya and Egypt. Its body is light yellow-brown, and its abdomen is pure white. The number of slender-horned gazelles is very rare and has been listed as an endangered species by the International Union for Conservation of Nature (IUCN).

After decades of war, Iraq's finances are under great pressure, and there is a lack of funds to provide protection and food for the slender-horned gazelles. In addition, climate change and land aridification have caused the lakes to dry up and the vegetation to decrease. The barren land has become so dry that it cannot be restored. The remaining slender-horned gazelles and their children are chewing on the dry grass with little nutrition, waiting for death to come.

Hungry Slender-horned Gazelle | References [5]

The reserve's director said he had allocated a fund of more than $68,000 to save the slender-horned gazelles in the Savar reserve, but for the carcasses lying on the barren grounds, it was too late.

Mountain lion killed in car accident

Last week, a female mountain lion, numbered P-54, died in a car accident in the Santa Monica Mountains in the United States.

It is not the first victim in the family. Four years ago, its mother P-23 was hit by a car on the same road and died. P-23 was only 5 and a half years old when she died, in the prime of life. P-54 was only one year old at the time and had just learned to live on his own when he lost his mother.

Mountain lion (Puma concolor) cub | Santa Monica Mountains National Recreation Area from USA / Wikimedia Commons

In 2020, P-54 gave birth to five children, but only P-97 and P-98 grew up safely, and the other three died. However, just two months ago, a passing vehicle once again took away P-54's family - the one-and-a-half-year-old P-97 was also hit and killed by a car while crossing the highway. What's even more sad is that people had decided to build a wildlife bridge on the highway at that time, and the day P-97 died was the day before the construction of the wildlife bridge began.

P-54 is the 29th mountain lion killed by a vehicle in the area since 2002. But car accidents are not the only danger they face: the dense network of roads and highways also restricts the range of mountain lions in Los Angeles, greatly reducing their genetic diversity. The combination of car deaths, inbreeding, and urban sprawl has given the area a 25% chance of extinction within 50 years.

Mountain lion | Bas Lammers / Wikimedia Commons

The wildlife bridge will be completed in 2025. By then, mountain lions and other animals that have been genetically isolated by the road will have a safe passage of their own. Hopefully, this safe passage will allow wildlife to move toward a safe future.

References

[1] https://academic.oup.com/mbe/advance-article/doi/10.1093/molbev/msac125/6604544

[2] https://phys.org/news/2022-06-cambodian-world-largest-freshwater-fish.html

[3] https://www.livescience.com/mass-little-penguin-die-off-new-zealand

[4] https://www.livescience.com/largest-python-in-florida-found

[5] https://phys.org/news/2022-06-parched-iraqi-gazelles-dying-hunger.html

[6] https://phys.org/news/2022-06-mountain-lion-p-vehicle-years.html

Author: Cat Tun

Editor: Mai Mai

This article comes from the Species Calendar, welcome to forward

If you need to reprint, please contact [email protected]