In a transparent square glass box, a snail is slowly wriggling.
It is an amber snail, a kind of snail distributed all over the country.
It originally lived in those dark and damp places, such as grass, ditches and so on. It not only likes heat and humidity, but also can tolerate drought and cold. It can also float on aquatic plants and water surfaces. It feeds on humus, lichens, fungi, mosses, algae, young shoots and leaves of plants, etc.
The shell size of amber snails varies greatly, usually long oval, with 3-4 spiral layers, shell height 5-15 mm, width 3-8 mm, shell quality is thin, shell surface is light yellow or yellowish brown , the body is transparent or translucent, and shiny.
But for the snail in the glass box, the two tentacles were particularly swollen, and compared to normal amber snails, they looked like two lumps of abominable growths.
Moreover, in its transparent body, one can clearly see some things inside, but it is not its internal organs.
Suddenly, the speed of its squirming increased, and it squirmed frantically at a speed that snails usually cannot achieve.
Its two swollen tentacles reflected bright light, like two drill bits, constantly rotating, flickering and changing.
"Students, this is a snail infected with parasites. The colors and light you see are actually a large number of parasites wriggling in its body."
In the biology class of this university, following the teacher’s words, a ten-fold slow-motion video was played on the teaching screen. It was still such an amber snail, and the students saw the creepy details. It was really not a natural luster. .
It is the snail that is full of parasites, one by one, they are constantly pushing and beating.
"That's Didiscolumba, and they're changing the shape of the snail's body and controlling the snail's brain."
As soon as the image on the teaching screen was changed, the bidisc flukes appeared under the camera, looking very large parasites.
Some of these biology students frowned, some were curious, and some already knew something.
"First, the snail ate the eggs of the bidiscoid fluke." The middle-aged man's teacher said, "This is how the parasite enters the host's body."
"Afterwards, the eggs will develop into sporangia, which are mainly parasitic in the liver of the snail. At this time, the snail still has no abnormal behavior. It may not even know that there are worms in its body, and eat the nutrients it has ingested so hard. Matter is constantly being stolen by parasites. We are not snails, so we are not sure about this, nor do we know exactly how they feel."
There was a chuckle in the classroom, but the students quickly fell silent.
They watched the simulated images on the screen, demonstrating how the parasite grows cercariae, how it grows, and then branches out from the snail's body, enters the two tentacles, and then forms a complete sporangia, which is full of Full of larvae.
It is they that make the snail's tentacles continue to expand, so that they cannot shrink normally, and can only hang out brightly.
Looking at these pictures, some students really feel that this snail parasitized by Didiscolumba is too pitiful.
"Once it enters the eye stalk of the snail, Didiscolumba begins to be able to control the host. The snail originally likes to be active at night, but after being controlled, it will become active during the day and in places with sufficient light, and the speed of movement is normal. As much as three times that, which may be the physiological limit of snails."
The teacher pointed to the diseased snail in the glass box on the podium, its tentacles flashing like neon lights.
"The way Didiscoides controls snails has not yet been researched, students, I will see you in the future.
But this kind of parasite is really smart. They make the snail colorful, make it lose the sense of fear, walk swaggeringly in the sun, so eye-catching, and also control the snail to climb higher leaves, those special conspicuous place. for what? Just for the birds to see. The bird saw that there was something shiny there, probably in the shape of a bug, so it flew over and ate it in one bite. Those are actually the tentacles of the snail, which are full of bidiscoids. "
The teacher paused, picked up the chalk and wrote on the blackboard, emphatically saying: "Aggressive mimicry, here is a situation where the parasite benefits."
Aggressive mimicry, a biological concept, in short, organisms use mating promises, false food and other means to lure prey into being fooled.
Nepenthes, for example, imitate flowers to trap nectar-harvesting insects. It is the wisdom of nature to eat, survive and reproduce.
"The snail is the first intermediate host." The teacher wrote on the blackboard while preaching: "Birds are the second intermediate host. After the bidiscoid enters the body of the bird, it will breed there again, and then the eggs will be carried by the bird. The poop goes out, the bird poop gets eaten by other snails...the cycle repeats."
The students got a little goosebumps when they heard that the bidisc fluke uses snails as false food, and the prey is birds.
A tiny parasite, only a hair's breadth in size, has such sinister and grotesque tricks.
And it can distinguish between day and night, high and low, conspicuous and hidden.
Whether it's intelligence or instinct, it's amazing.
"Teacher, can Didiscolumba control birds?" A male student asked.
"There's no evidence of that yet."
"Then can it enter the human body?"
"It's not a human parasite." The teacher smiled and said, "Our human body is more complex than snails and birds, and we have a stronger defense system, which can block the double disc fluke. But we also have many parasites to deal with, such as iron nematodes Difficult to do, too. I know what you're asking, no, there's no such thing as a parasite that can control human thought and behavior."
"Maybe there is still a kind called Money." The teacher added, "The English name is Money, and the Latin name is Aes."
There was another chuckle from the students in the classroom.
Indeed, humans are not snails, and parasites are not so easy to control.
At the same time, in the transparent glass box, the snail was wriggling frantically, wriggling, motionless for a second.
…
Beep, beep, the phone is connected.
"Hello, is this Wang Jiawei's mother? I'm Li Yuhao's mother. Yes, our son lives in the same dormitory."
"Hello, Yuhao's mother, what can I do for you?"
"It's like this. Yu Hao told us last night that he and some classmates came to your house to have a party and spend the night there. I called him in the morning, but no one answered. It's almost noon now, and there is still no one. Answer, he hasn't come home yet. I also have Jiawei's number here, and several other classmates. I called them, but no one answered... "
"Is that so... Yuhao's mother, Jiawei's father and I are out of town for the past few days. Don't worry, young people must have parties until very late. They don't have to go to school today, and it's not unusual for them to stay up all night. Maybe they I haven't woken up yet, and no one is answering."
"I think so too, but it's always a bit weird... These kids didn't post on Moments. Which party didn't they post a few before?"
"Well... how about this, I asked the property management of the community to send someone to my house to see what's going on, maybe I'm drunk?"
"Okay, Jiawei's mother, I will trouble you then."
"Hey, why are you being polite, this is also Jiawei's party."
The call is over.
Less than half an hour later, the call was connected again.
"Hello, Yuhao's mother? Just now the security guard went to see, but no one was at home, and found that my garage was open. I looked at the picture, and a MV was driven away. I asked the security guard to check the monitoring of the community , the car was driven out last night, Jiawei drove the car, Yuhao and the others were all in the car..."
"What... Jiawei can drive? Here, where did they go?"
"I don't know yet, Yuhao's mother, it should be fine, the young people are just going crazy, let's not mess up."
"Stop talking, call the police, let's call the police quickly."
"Wait, this matter hasn't gotten to the point yet, so don't make a fuss... Yuhao's mother, don't think Jiawei is driving the car, you think I only care about my son. What if they are the ones who did the bad things? We don't know, I mean if, if they touch marijuana, ecstasy stuff, calling the police is going to destroy them, we have to think about the kids."
"Hey! You... Are they safe now? Isn't it our first consideration! My Yu Hao is not the kind of person who can touch drugs."
"I'm just making an analogy, wait a minute, Yuhao's mother, look at Moments! I saw Jiawei just posted a Moments. Can you see if Yuhao has posted?"
"Ah, let me see, hey, yes, yes, yes! Yuhao also sent a message just now. The kid is here, why didn't he answer the phone? He didn't call back to report a letter, it scared me to death, ah, really .What does this circle of friends mean... 'I have seen God, and I am its incarnation in the human world.'”
"... Jiawei sent the same sentence, did they go to some concert and meet some idol?"
"Maybe, this child... Mother Jiawei, let's do this first, I'll call Yuhao again, and see if I don't beat him up when he comes home."
"Young people don't need to beat and scold when they go crazy, but this Jiawei, I'm going back to deal with him."