Li Di Chen Ke
On the coast of Southeast China, people frolicking in the sea occasionally see a coin-sized sky blue circular object floating on the surface of the water, looking elegant and mysterious, what are these small things?
Recently, this "bottle cap"-like creature has appeared in the waters from Dongshan Island in eastern Shenzhen to Orange Fishing Sand. After the staff of the South China Sea Fisheries Research Institute of the Chinese Academy of Fishery Sciences tested, it was confirmed that the creatures were silver coin jellyfish.
A silver coin jellyfish floating on the surface of the sea. Shenzhen Evening News reporter Li Jingchuan photographed
It is understood that this is the first time that a large number of silver coin jellyfish have been found in the waters of Shenzhen. Experts remind that although the toxicity of silver jellyfish is weak, it is still necessary to avoid direct contact. Today we're going to take a look at this type of marine life that sounds "rich."
<h1 class="pgc-h-arrow-right" data-track="44" > "early warning officer" of water changes in the sea</h1> area
"The genus Silver Coin Jellyfish is a genus of coelenterate phylum, Hydra, Tube Jellyfish, and Silver Coin Jellyfish. The circle in the center of the jellyfish body of this genus is called 'floating sac', like a small disc, the texture is hard, very light, slightly transparent, it looks like a silver coin, which is also the origin of the name of the silver coin jellyfish. Zhao Li, director of the Chengdu Huaxi Insect Museum, said that just listening to the name makes this creature feel "rich."
In fact, there is also a round sea urchin that lives by the sea, because it looks like a silver coin, and people often find it in the sand, so it is named sand coin. But the "important role" we are going to introduce today is the silver coin jellyfish, which can drift on the sea with the warm current, so it is also regarded as the "warm current indicator species".
Zhao Li said that when silver jellyfish appear in a water area, it is actually proof that the water body in the water is warm, which may be related to the high temperature in summer, or it may be that the warm current has reached the area.
Not only that, the horizontal distribution of silver coin jellyfish is also closely related to ocean currents, water masses and meteorology, in southern Fujian, fishermen call silver coin jellyfish "wēn mirror", using them as a warm current indicator of taiwan's summer flood of anchovies (tí) anchovies, thus very accurately predicting the arrival of anchovies in summer.
According to Zhao Li, anchovies is a general term for pelagic fish such as orchid, feather gill, golden sardine, fat-eyed herring, etc., which is the general name of all small fish active in shallow waters. It can be said that the silver coin jellyfish is the "early warning" of water changes in the sea area.
"Interestingly, silver jellyfish do not have the ability to swim, but can only 'go with the flow', drifting on the sea with the warm currents. Until the summer, they appear in groups, washed near the coast by the current, and even washed onto the beach, making the whole beach appear 'fantasy'. Zhao Li said.
<h1 class="pgc-h-arrow-right" data-track="45" > silver jellyfish is a "working boy combination"</h1>
Just now we mentioned that the circular circle in the center of the silver jellyfish body is called "floating capsule body". The floating capsule of such organisms is composed of dozens of thin concentric rings and dozens of radiating ribs, which have radiative septums inside and are filled with gas.
Zhao Li introduced that the silver coin jellyfish we see is not a single individual, but a "big family" composed of many individuals similar to water flies, all of which are "working boys", with a clear division of labor, some are specifically responsible for predation, some are specifically responsible for reproduction, and some are specifically responsible for helping the entire jellyfish float.
Silver coin jellyfish. Image source: Shenzhen Evening News
Among them, the core part of the silver jellyfish is the ventral surface of the floating sac, including the main vegetative body, the small vegetative body, the reproductive body and the finger-like body. "Silver coin jellyfish are floating filter-eaters, preying mainly on tiny plankton such as copepods and crustacean larvae. Silver coin jellyfish use finger bodies to capture these plankton, and their floating sac has a feeding mouth under the body for preying on and excreting waste, which is then sent to the nutrient body for digestion, and the absorbed nutrients are supplied to all individuals through the endosome's pipeline. He said.
According to reports, the genitals of the silver coin jellyfish are granular, growing at the base of the small vegetative body, arranged in several circles at the edge of the floating sac, each finger body has 3 longitudinal scattered short branches, the end of the short branches is expanded, there are many long tentacles around the floating sac, there are many spine cells that can secrete venom, which are used to prey on plankton, and are also the "weapons" used by the silver coin jellyfish to protect themselves.
"Each tentacle on the abdomen of the silver jellyfish has countless branches, and the tentacles do not sting or endanger life after touching a person, but may produce an itching sensation. If you rub your eyes or other weak places with a finger that has touched the tentacles of a silver jellyfish, the pain that follows will surely be unforgettable. Zhao Li said.
So if you come into contact with a silver jellyfish at the beach, how to do emergency treatment?
Zhao Li further explained that the sting of the silver coin jellyfish is not strong enough to cause serious damage, but it can cause skin irritation or small rashes. If you are stabbed by a silver jellyfish, you should first rinse the place where you were stabbed as soon as possible, rinse off the venom as much as possible, and then you can apply some hypoallergenic drugs. In general, no special treatment is required, only the puncture is rinsed.
Editor: Zhang Shuang
Review: Yue Liang