When it comes to prehistoric creatures, the first thing that comes to mind for many people is the extinct dinosaurs. However, some small animals that appeared earlier than dinosaurs, such as three-eyed dinosaur shrimp and fairy shrimp, have survived from ancient times to the present.
<h1 class="pgc-h-arrow-right" > "little monster" appeared in the water</h1>
To the surprise of the villagers in the western suburbs of Pengzhou City, Sichuan Province, in the early years, some shrimp, fish and other "monsters" appeared in the local rice fields from time to time. These things are about 7 centimeters long. They have a large back shell on their heads. Their lower limbs have many feet like centipedes and many legs. They swim fast and have smooth bodies. You can't catch them with your bare hands. So, where are they "sacred"? Scientists have confirmed that they are ancient crustacean horseshoe crabs, commonly known as three-eyed dinosaur shrimp.
Shortly after the "three-eyed dinosaur shrimp" appeared, another creature, which was called strange by the public, suddenly appeared. They swim in the water like fish, but don't look like fish. The most interesting thing is that these small animals like to "backstroke" in the water, which is very cute. Their eyes are black, protruding on the sides of the head, and their bodies are pale yellow or light green. Their forked tails are red and each has more than 10 pairs of feet on its abdomen. Later, experts confirmed that this is also an ancient crustacean of the same age as the dinosaurs, also known as the fairy shrimp. They are all called "living fossils".
<h1 class= "pgc-h-arrow-right" > shrimp is not shrimp</h1>
The three-eyed dinosaur shrimp and fairy shrimp are primitive crustaceans that mostly live in inland freshwater or salt lakes. Most of them have short reproductive cycles and high reproductive rates, producing dormant eggs that are resistant to drying and extreme temperatures, which are spread by wind and dust and birds. As a result, they are common in intermittent bodies of water, and their appearance and disappearance are often sudden.
In fact, there is only one family of crabs in the order Dorsalaceae, commonly known as dinosaur shrimp, tadpole shrimp or shield shrimp. Three-eyed dinosaur shrimp get their name because they have three eyes, a pair of black compound eyes on either side, and a white photosensitive eye in the middle. Their carapace is large and cool, like the shield of ancient warriors, known as the shield shrimp in Oceania; the shape resembles a tadpole, also known as the tadpole shrimp in the United States; because of its appearance resembling the marine animal horseshoe of the arthropod phylum, the horseshoe crab is also called "horseshoe crab" in China. Although they are called "shrimp" and "horseshoe crab", they are similar to each other and belong to arthropods, but they are not closely related to each other.
Although the fairy shrimp has a "shrimp" in its name, it is not actually a shrimp. The scientific name of the fairy shrimp is twig-frontal insect, which belongs to the arthropod, crustacean subphylum, gill-footed order, acetomorphate, plutoaceae, and mycoptera. Most of the branches are distributed in freshwater lakes or ponds, there are "freshwater shrimp" and "shrimp"; at the same time, because of its beautiful appearance, bright color, beautiful growth, slender wings, like a fairy, its backstroke (belly facing upstream water) is light and elegant, has the reputation of "fairy", in foreign countries also has the reputation of "fairy shrimp" and "shrimp to the sky", however, the term "fairy shrimp" not only refers to the frontal insect, it is a broader concept, but also includes the animals of the frontal insect family where the genus of the frontal insect is located. It even includes animals that are similar to it in the entire order Achonadium.
<h1 class= "pgc-h-arrow-right" > living fossils</h1>
The three-eyed dinosaur shrimp and the fairy shrimp are both ancient species that lived at the same time as the dinosaurs and are one of the most representative creatures in prehistory, known as "living fossils". However, although they appeared on Earth earlier than dinosaurs, they still maintain their first appearance with little evolution. They are not affected by biological evolution mainly due to their unique "stagnation" ecological evolutionary characteristics. That's why dinosaurs went extinct, but we can still see them until now.
A few three-eyed dinosaur shrimp undergo sexual reproduction, and some populations are hermaphrodite. The most common is parthenogenesis. Different breeding methods produce two different types of eggs: summer eggs produced by parthenogenesis, whose shells are relatively thin, begin to develop and hatch after birth to ensure population numbers; winter eggs produced by gender reproduction, with thick shells, will enter the "diapause period" under harsh conditions such as drying and freezing, and even stagnate for decades or more. These eggs can also be spread with the wind or expanded by swallowing and excretion by waterfowl. For the three-eyed dinosaur shrimp, the winter egg may be the protagonist of its evolutionary miracle.
Compared with the three-eyed dinosaur shrimp, the eggs of the fairy shrimp have a stronger ability to continue. Protected by a hard insulated shell, fairy shrimp eggs can withstand high temperatures and freezes, and can even survive in boiling water. A tiny egg can wait ten thousand years until the day there is water and the environment suitable for hatching. They can be called miracles of the biological world.
<h1 class= "pgc-h-arrow-right" > "Cordyceps sinensis" at sea</h1>
Although the three-eyed dinosaur shrimp and fairy shrimp are small and insignificant, some of them are nutritious and of high economic value. They can be used as food for animals, fish, poultry and livestock, and even as food for humans.
Fairy shrimp has long been a delicacy in China. For example, the people of Jiaozhou Bay make it into shrimp paste. Fairy shrimp is a high protein and low fat food.
In recent years, due to the shrinking area of the Jiaozhou Bay wetland and the backfilling of a large number of saline and alkali land, the fairy shrimp has almost disappeared. In order to let this small creature continue to reproduce, some people began to raise fairy shrimp. Since the cultivation of fairy shrimp must be carried out in saline and alkali land, so farming can also protect the limited saline land of Jiaozhou Bay, every spring many migratory birds that like to eat fairy shrimp migrate to the vicinity of Jiaozhou Bay, which plays a role in maintaining ecological balance.
The three-eyed dinosaur shrimp feeds mainly on small aquatic organisms, such as mosquito larvae in the water. They can also remove weeds from rice paddies and are very environmentally friendly "herbicides" and farm guards. As early as the early 1920s, the weeding effect of the three-eyed dinosaur shrimp was discovered. In Japan, some farmers have long used three-eyed dinosaur shrimp to control rice field weeds as a pesticide substitute for growing rice, and vividly call it "grass worms". At present, the pollution of pesticides to the environment has become a social problem, and its weeding effect is worthy of attention.