Species name: peach blossom jellyfish
Chinese alias: peach blossom fish, parachute fish, hydroid jellyfish
Latin scientific name: Craspedacusta sowerbyi
English name: freshwater jellyfish
Family and genus classification: Cnidaria, Hydrozoa, Freshwater Jellyfish, Hydrozoa
Cnidaria (Cnidaria) Hydrozoa ) Craspedacusta is an animal that lives in fresh water, so it is also known as freshwater jellyfish. Sowerbyi's peach jellyfish (C. sowerbyi), which is widely distributed in freshwater in the northern hemisphere, is about 2 centimeters (0.8 inches) in diameter and has hundreds of short tentacles on the edges of its bell-shaped body. There is a change of generations. The polypoid body is about 2 mm (0.08 inches) high, has no tentacles, and produces jellyfish bodies by budding. Jellyfish are divided into male and female bodies, which lay eggs and sperm respectively. After fertilization, they become free-swimming larvae, which fall to the surface and grow into polyps.
Appearance characteristics
[Edit this paragraph]
The appearance of the peach blossom jellyfish is like an open umbrella or an inverted bowl, which is called an umbrella. There are many thin linear tentacles on the edge of the umbrella, which are its prey organs. The mouth faces the bottom of the umbrella, located at the end of a tube, with 4 lips. Food is swallowed here, and the indigestible residue is still excreted through the mouth, so the peach blossom jellyfish has a mouth but no anus. There is a horizontal membrane on the edge of the umbrella, which is the unique characteristic of polyps.
Peach blossom jellyfish, commonly known as "peach blossom fish" and "parachute fish". Hydrojellyfish has a transparent body, slightly milky white, about the size of a thumb, with a diameter of about 0.1 cm to 1 cm, and about 256 tentacles. It can be divided into seven levels according to its length. It floats and sinks by the contraction of the umbrella and the up and down movement of the tentacles. in water. The polyps are underdeveloped, only 2 mm high, and have no tentacles. Freshwater product. Through the crystal clear water, thousands of peach blossom jellyfish, the size of coins and mysterious elves, are opening and closing in the water, dancing gracefully; when a ray of morning light shines on the water, the jellyfish will float to the surface to enjoy the sunshine; and A gust of autumn wind passed by, and the elves were slowly lurking around the green water plants. The peach blossom jellyfish floats quietly, like petals of peach blossoms floating in the water. It is headless and tailless, crystal clear and soft as silk. It opens and shrinks in the water, floating up and down, leisurely and contented, like a parachute rising and falling slowly in the air, and looks extremely graceful in the crystal clear water pool.
The peach blossom jellyfish is a rare animal in the world. It usually appears for a short time, so it is difficult to find. Because they mostly appear in early spring when peach blossoms are in full bloom, some are pink and swim in the water, looking like peach blossom petals floating on the water. Therefore, they were called "peach blossom fish" in ancient my country. But it is clearly pointed out that peach blossom fish "is not a fish, it is born in water, so it is called fish; it is born when peach blossoms bloom, so it is called peach blossom fish". This correct understanding was a remarkable achievement hundreds of years ago.
Distribution range
[Edit this paragraph]
Worldwide distribution, the countries where Peach Blossom Jellyfish was distributed in the UK in 1880 are: Japan, South Korea, and the Philippines , Russia, the United Kingdom, France, Germany, Italy, Belgium, Sweden, the Netherlands, Spain, Poland, Romania, the Czech Republic, Denmark, Australia, the United States, Canada, Panama, Chile, etc., there is no record in our country. In 1959, a new species of Craspedacusta kou was reported in Taiwan. Kramp (1961) believed that this species was not a new species but Craspedacusta kou. This needs to be confirmed. Japan's Ise peach blossom jellyfish in 1922 is only distributed in Japan, and only one specimen was collected.
It is found in Sichuan, Zhejiang, Hubei and other places in my country. According to more than 50 years of investigation and research by domestic experts, from 1907 to 2002, peach blossom jellyfish was found in 14 provinces, 53 cities and counties in my country in 95 years, and it was only discovered once in some areas, such as Changsha, Chengdu, Sichuan Irrigation County, Xiamen, Xinyang, Henan, Taiwan, Hong Kong, etc., and a few areas appear almost every year. There are many types of peach blossom jellyfish in my country, they are widely distributed and recorded early, which is unmatched by other countries.
Living environment
[Edit this paragraph]
Peach Blossom Jellyfish is a genus. The body of the peach blossom jellyfish is composed of only two layers of cells. There is a cavity in the body, which is where food is digested and absorbed. It is equivalent to the intestines of other animals and is a coelenterate.
The peach blossom jellyfish is crystal clear and swims in the water, looking like peach blossom petals floating on the water. The life history of the peach blossom jellyfish consists of alternating generations of asexual reproduction and sexual reproduction. The polyps (the "childhood" of the jellyfish) have very low environmental requirements, but once the jellyfish is separated, it has very high requirements on the environment and water quality. When the environment adapts, the polyps will naturally separate from the jellyfish; when the environment is unfavorable, the polyps will be adsorbed underwater or in rock crevices for a long time to survive for generations.
When an expert who has studied jellyfish for more than 40 years discovered peach blossom jellyfish in Wuxi Cuihu Lake, he scooped out the lake water with a measuring cup and measured the pH value to be 6.4. He Zhenwu said that this slightly acidic water environment is most suitable for the growth of jellyfish. The water source mainly comes from the nearby Luding Mountain stream.
Life habits
[Edit this paragraph]
The peach blossom jellyfish is crystal clear and swims in the water with graceful posture. Its umbrella body constantly contracts and expands, forcing the water in the lower umbrella cavity out of the body, thereby slowly swimming in the opposite direction. When food is encountered, the nematocysts on the tentacles shoot out stinging wires, sting the prey, anesthetizing it instantly, and then bring it into the mouth with the tentacles and swallow it into the stomach. Peach blossom jellyfish mostly feed on water fleas, small nematodes, small ringworms, small tadpoles, small fry, etc.
The peach blossom jellyfish is the lowest-level organism on the earth. The peach blossom jellyfish is the most primitive and lowest invertebrate coelenterate. It has a history of 650 million years and appeared hundreds of millions of years earlier than the dinosaurs. Known as a "living fossil" in the study of biological evolution, its unique genes are of great significance to modern genetic engineering research. The peach blossom jellyfish has extremely high requirements for the living environment. The water quality must not be polluted. It is rare in living organisms and extremely difficult to prepare specimens. It is listed as the world's highest-level "critically endangered creature" by the country, and is also known as the "Giant Panda in the Water".
Growth and reproduction
[Edit this paragraph]
Why do peach blossom jellyfish suddenly appear and disappear quietly after a few or ten days? This depends on their To answer the question of the laws of reproduction. The peach blossom jellyfish seen in my country in early spring is a mature jellyfish body, divided into male and female. It was previously thought that male and female peach jellyfish were indistinguishable in appearance. From our observation, the tentacles are long and slender, and those extending upward are female. The tentacles are short and thick, and those extending downward are male. The male and female release eggs and sperm into the water. The eggs are fertilized and develop into a tiny planktonic larvae covered with cilia. After one end of the larvae comes into contact with foreign objects such as rocks and soil, it becomes fixed and develops into a very small branch-shaped polyp. The polyps can survive the hot summer and cold winter, and in the following spring, they will bud out and reproduce to produce jellyfish. After the jellyfish matures, it undergoes sexual reproduction. The polyp we discovered in Zigui in 1993 was only 0.3 mm long. In 2002, another polyp was discovered under artificial breeding conditions. The jellyfish undergoes sexual reproduction to produce polyps, and the polyps undergo asexual reproduction to produce jellyfish. This is called alternation of generations in zoology.
Species History
[Edit this paragraph]
In zoology, the world’s first record of the peach blossom jellyfish was in 1880. The specimen was collected from London, England. Named Craspedacusta Sowerbyi Lankester (1880). About half a century later, it was discovered one after another around the world, mainly in temperate regions such as Asia, Europe, and the Americas, and also in Oceania. The peach blossom jellyfish in my country was first discovered in 1907. It was collected by Japanese people and named Yichang peach blossom jellyfish by Japanese scholar Qiu Qian [C.kawaii (Oka, 1907)].
There is a record of "Peach Blossom Fish" in "Guizhou Chronicles" in the 37th year of Wanli in the Ming Dynasty. This is the earliest record of peach blossom jellyfish in the world. The Peach Blossom Jellyfish was described in detail and vividly in the "Collection of Ancient and Modern Books" in the third year of Yongzheng's reign in the Qing Dynasty (1726): "The Peach Blossom Jellyfish is shaped like an elm pod, with different sizes. It squirms and swims in the water, and when it moves, it shrinks and shrinks, just like a human being. The fingers are in a state of retraction, not knowing how to avoid people, and the same is true when taking it out of the water and looking at it, it is just like a twist of saliva, and it is soft and has no shape. There is a record that "peach blossom fish come out of the Chixi River and can only be seen when the peach blossoms bloom. There are two kinds of red and white, and there are no flowers after they bloom." Other ancient books also include: "The peach blossom fish is round in shape, as thin as a cicada's wing, and floats on the water surface like a splay." When it appeared, it was said: "The peach blossom is life and death. Once the peach blossom is gone, there is nothing." According to the investigation According to the information obtained, it is certain that our country’s understanding of peach blossom jellyfish is at least 270 years earlier than that of European and American countries.
In Zigui, it can be said that "Peach Blossom Fish" is a household name, and such a beautiful and moving legend is spread.
King Zhaojun of Han married outside the Great Wall for the sake of reconciliation between Han and Hu. Zhaojun returned to his hometown to visit relatives before leaving the fortress to get married. He held the pipa in his arms, sat on a boat on the Chixi River, and played a pipa line affectionately. He couldn't help but shed tears. The crystal teardrops dripped into the river and suddenly turned into a transparent peach fish.