Jellyfish are cute and delicious? But being stung by them is terrible and can be fatal!

Jellyfish salad is refreshing and appetizing, and is a favorite of many people. However, although jellyfish looks harmless to humans and animals, it is still a scary creature for people living in coastal areas.

If you are stung by it, you will feel uncomfortable for several days at best, and it may be fatal in severe cases. Why are jellyfish so "toxic"? What about the nutritional value of jellyfish after being made into food?

01

What kind of creature is a jellyfish?

Jellyfish are invertebrate molluscs, a type of jellyfish, that feed on plankton, small crustaceans, polychaetes, and even small fish. They mainly live in coastal areas of China, from the coast of Guangdong and Hainan Island to Liaoning. [1]

▲Figure: Chinese Food Composition Table, 6th Edition, Volume 2

Jellyfish have a round or bell-shaped body with tentacles and oral arms. The outer umbrella is smooth, and the middle gelatinous layer is thick and hard. The diameter of a large jellyfish umbrella can reach 25 to 60 cm [2]. The tentacles are digestive organs and also hunting weapons. They have many poisonous threads that can eject venom.

▲Figure: References [1]

02

What happens if you get stung by a jellyfish?

The jellyfish may look cute and harmless, but it is actually a poisonous killer.

Every year from June to October, jellyfish will swim to the surface in groups to mate and lay eggs. These months are also the hottest time of the year, and many people will go to the beach to play. Because jellyfish are transparent in the water, they are not easy to be discovered, so it is easy to be stung. [3]

In August 2015, a 4-year-old girl died from a jellyfish sting at Xiajiahezi Beach in Dalian, Liaoning Province. The girl's mother was stung on the leg when she kicked the jellyfish.

**Jellyfish are highly toxic. Their tentacles are covered with poisonous threads that can eject venom, the toxic component of which is jellyfish toxin. When the human body comes into contact with the tentacles of jellyfish, the nematocysts will immediately release a large amount of jellyfish toxin, causing symptoms of poisoning in the human body, such as contact dermatitis, itching and pain, skin congestion, and even local necrosis. **Itching and pain symptoms can last for 10 to 20 days, and severe cases may not heal for several months. [4, 5]

Not just jellyfish, many jellyfish are not easy to mess with, Image source: Tuchong Creative

If a jellyfish stings you severely, it can also cause systemic symptoms, such as coughing, chest tightness, asthma, movement disorders, heart failure, vomiting, diarrhea, liver and kidney damage, and more seriously, it can lead to anaphylactic shock. [4, 5]

Statistics in my country show that in the past 20 years, there have been approximately 2,200 cases of jellyfish stings in coastal tourist areas, including 13 deaths, all of which were caused by anaphylactic shock after the sting. [4]

If the cardiovascular system is compromised, fainting and shock may occur within a few minutes or even a minute, with the skin turning from pale to cyanotic, leading to death in a short period of time. [4]

03

What should you do if you are stung by a jellyfish?

**There is no specific medicine to treat jellyfish stings. **If you are stung, you should take immediate measures to relieve the symptoms.

You can use tweezers to remove the jellyfish's stinging sacs, then rinse the sting with seawater. Do not use fresh water to rinse, because fresh water has a lower osmotic pressure and can cause the stinging sacs to burst and release toxins, aggravating symptoms. Do not use vinegar to clean, as this may aggravate the pain. Do not squeeze the sting with your hands. [4]

After simple treatment , go to the hospital immediately for appropriate treatment.

04

What nutrients does jellyfish have?

**Jellyfish is edible.** my country is the first country to eat and use jellyfish. The traditional processing method is to soak it in lime and alum, squeeze out the water in the body, wash it, and pickle it. After this processing, it becomes the commonly eaten jellyfish product. [6]

After processing, the jellyfish's cap will become a round, translucent skin, which is the jellyfish skin; the shape of the oral arm part remains unchanged, which is called the jellyfish head.

The most common dishes are cold jellyfish shreds (shredded jellyfish skin) and cold jellyfish heads, which have a crispy texture and are a favorite of many people.

Tuchong Creative

Jellyfish skin and jellyfish heads are both low-fat, low-cholesterol foods, and can be eaten safely even by people with obesity or abnormal blood lipids.

Jellyfish also has a high calcium content. The calcium content of jellyfish skin and jellyfish head is 150 mg/100 g and 120 mg/100 g respectively, which is considered to be relatively high among aquatic products. If you eat 100 g of shredded jellyfish salad, you can meet 19% of your daily calcium requirement, which is quite good. [7]

The purine content of jellyfish silk is also very low, with a total purine content of only 9 mg/100 g, making it a low-purine food . People with high uric acid levels and gout can eat it with confidence. [7]

In addition, it is important to remind you: Don’t think that eating jellyfish, which is rich in collagen, can beautify your skin.

So, **don't count on eating jellyfish for beauty, it can supplement calcium, **and it tastes good and is very chewy.

Summarize:

Although jellyfish taste delicious, if you encounter them at the beach, you should stay away from them and never catch them. Even if they are dead, don't touch them, or you may get stung.

References:

[1] Zhang Yuying, Chai Yanping, Qin Lei, Xue Jia, Xu Xianbing, Du Ming, Dong Xiuping. Analysis and evaluation of nutritional composition of different tissues of jellyfish[J]. Food Science, 2017, 38(02): 133-138.

[2] Hong Huixin. Jellyfish and jellyfish[J]. Bulletin of Biology, 2002(02):13-16.

[3] Huo Shuhua, Liu Jiqiang, Yang Hongchao, Tian Yingping, Huang Suzhen, Liu Huijuan, Xu Shuguang. Clinical analysis of 822 cases of jellyfish stings[J]. Chinese Journal of Emergency Medicine, 2015, 24(12): 1471-1472.

[4] Zhang Chongyang, Meng Qingyi, Qiu Zewu. 2014 Chinese expert consensus on the treatment of jellyfish stings[J]. Clinical Misdiagnosis and Mistreatment, 2014, 27(10): 1-5.

[5] Huo Shuhua, Xu Shuguang, Su Xiaoyun, Tian Yingping. Research progress on jellyfish stings[J]. Chinese Journal of Emergency Medicine, 2017, 26(02): 249-250.

[6] Hao Gengxin, Yang Shen, Dai Yanbin. Analysis of nutritional components of jellyfish skin and extraction of collagen[J]. Agricultural Products Processing (Journal), 2011(04):65-69.

[7] Yang Yuexin. Chinese Food Composition Table 6th Edition Volume 2[M]. Peking University Medical Press, 2018

Author | Xue Qingxin, member of Chinese Nutrition Society, registered nutrition technician, health manager, public nutritionist

Review | Chen Shengjun Associate Researcher, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences

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