I. Overview
Craspedacusta, also known as "peach blossom fish" and "parachute fish", is a small freshwater living jellyfish of the hydra class, with 11 species recorded. The jellyfish has a diameter of 1.5~2 cm, many tentacles, a thick margin membrane, and its hydra-type stage is only a few millimeters in size. The edges of the bell-shaped body have hundreds of short tentacles, lending buds to produce jellyfish.
When the peach blossoms open in the spring, peach jellyfish appear one after another, they have pink gonads, a transparent umbrella top, floating in the water, just like peach blossoms falling into the water, the ancient people on the mainland called it "peach blossom fish".
The peach blossom jellyfish is an endangered ancient and rare coelenteric animal, first born about 550 million years ago, much older than dinosaurs, so it is known as a veritable "living fossil".
Widely distributed in China, Japan, South Korea, Russia, Britain, France, Germany, Italy, Australia, the United States, Canada, Panama, Chile and other places. It is distributed in the mainland Sichuan, Zhejiang, Hubei, Jiangxi, Hunan and Northeast Songhua River Basin, Taiwan, Hong Kong and other places
2. Living environment
(1) The clams of the peach blossom jellyfish "when they were young" do not have high requirements for the environment, but once the jellyfish is separated, it will have high requirements for the environment and water quality. From this, it has also evolved that when the water environment conditions are suitable, the peach jellyfish naturally separates the jellyfish; When the environment is unfavorable, the clams are adsorbed to underwater stones for a long time.
(2) Peach blossom jellyfish mostly feed on zooplankton such as sword water fleas, small nematodes, small ringworms, small tadpoles, and small fish fry. The spiny sac on the tentacle can shoot out the spiny wire, which is paralyzed after hitting the catch, and sent into the mouth with the tentacle.
(3) Peach jellyfish live in fresh water and are found in artificial lakes, ponds, lakes and rivers. They like to grow in warm waters, the temperature is between 25~32 °C, and the pH value of their living waters is about 6.5. They prefer a low-light environment, distributed in the upper or surface layer of water in the morning and evening, and distributed in the middle and lower layers of water when the light is strong and the water temperature is high at noon.
3. Level of protection
If the water is polluted, the peach jellyfish may become extinct in a few days, and its preciousness is called "water giant panda", which belongs to the world's highest protection level of "critically endangered species" and is a first-class protected animal in the red list of protected animals in China.
In the past hundred years, 11 species of peach jellyfish have been found in the world, and although they are widely distributed in the mainland, the natural environment is threatened due to the pollution of the water quality of the water body in which the peach jellyfish lives. Among the nine species of peach jellyfish distributed in mainland China, Yichang peach jellyfish, Xinyang peach jellyfish, and short-handed peach jellyfish are listed as the most advanced critically endangered species on the national red list of endangered animals. Hangzhou peach jellyfish, Leshan peach jellyfish, Sichuan peach jellyfish, Chinese peach jellyfish and Chuxiong peach jellyfish are listed as endangered species.
In September 2022, in Chengdu's Crescent Lake, citizens found four jellyfish swimming one by one in a basin, each about 2 centimeters in diameter, and after expert identification, found that this was the peach blossom jellyfish. In addition to Sichuan, many peach blossom jellyfish have appeared in Beijing, Yunnan, Hunan, Chongqing and other places. These incidents also show that the mainland has achieved results in environmental protection work in recent years, and when the environment improves, the indicator creature of the peach blossom jellyfish will naturally return.
Peach jellyfish has important ecological, academic and ornamental value, once this precious species goes extinct, it will not only lose the diversity of mainland species, but also the loss of the traditional culture of ancient "peach blossom fish". Therefore, it is necessary to strengthen the protection and restoration of the environment, so as to play a role in saving the peach jellyfish.