Classification of jellyfish

Jellyfish (jellyfish, or jellyfish, nettle fish) h m: izhé.

[Edit this paragraph] Introduction

It is a marine coelenterate, belonging to coelenterate phylum, Cephalopoda, Rhizopus and jellyfish. Jellyfish is umbrella-shaped, translucent, white, cyan or yellowish. The diameter of jellyfish umbrella can exceed 45cm, and the maximum can reach1m. Eight thickened (shoulder) wrists under the umbrella healed to make the mouth disappear (replaced by a suction cup secondary mouth). There are many rod-shaped and filiform tentacles in the lower mouth and wrist, and there are dense stinging silk sacs on them, which can secrete venom. Its function is to release venom paralysis when it comes into contact with small animals for food. Jellyfish are widely distributed in tropical, subtropical and temperate coastal areas. The common jellyfish in China are edible jellyfish with smooth umbrella surface and only filaments on the mouth and wrist or rod-shaped jellyfish with rods, and Mylabris with many small warts on the umbrella surface.

The life cycle of jellyfish has experienced fertilization, aphid development, larval development, jujube cracking and jujube butterfly formation. In addition to the sexual reproduction of sperm and eggs in vivo, the salamander larvae of jellyfish will also produce creeping roots to form foot sacs, and even split into multiple disks, which will greatly increase their individual number through asexual reproduction.

In coastal waters, this gentle and elegant animal often attracts people's great love and interest. However, don't indulge in hugging such animals in the sea, the consequences and prospects are mostly bad. The stinging sac of fresh jellyfish contains venom, which is composed of a variety of substances rich in skin. People who catch jellyfish or swim at sea will be injured by touching the tentacles of jellyfish, causing redness, swelling, heat and pain, epidermal necrosis, and symptoms such as chills, irritability, chest tightness and unbearable wound pain. Severe cases may be life-threatening due to dyspnea and shock. In midsummer, it is the peak season for jellyfish to grow, and it is also the peak season for fishermen to fish at the seaside or tourists to be easily stung when swimming at the seaside. Jellyfish are distributed in the coastal waters of China, and there are many kinds, and the nature and harm of the toxins secreted by them are not the same. However, due to the difference of individual sensitivity, jellyfish stings only have general allergic reactions, which can lead to death seriously. We must pay attention to effective prevention and active rescue treatment.

Jellyfish venom can cause different degrees of harm to human body. For example, sea wasp jellyfish can secrete venom similar to cobra, which is the most harmful to human beings and can kill people within 5 minutes after being stung. After the jellyfish stung the human body, it took many days for the patient to get rid of the pain. There are common jellyfish floating in the Yellow Sea off the coast of China, which can secrete peptide poison. Macular jellyfish are mainly distributed in the coastal areas of Guangdong and Guangxi, and have certain toxicity.

China has a vast sea area, and a considerable number of jellyfish stings occur from July to September every year. In the past, fishermen mainly caught jellyfish, and recently some patients were stung while swimming at the seaside. For example, in recent years, more than 3,400 people have been stung by Qinhuangdao seaside. According to the statistics of Beidaihe Seaside Hospital, a tourist resort, during the five years from 65438 to 0989, 3030 cases of * * * were treated, of which 0.3% were fulminant allergic pulmonary edema and 4 cases died (all severe shock).

Jellyfish toxins are stored and distributed in gill boxes. The 65,438+0g card box contains 55 million single-needle card boxes. Generally, after fishing, its toxicity can disappear quickly after processing. Animal experiments have proved that jellyfish toxin is harmful to the heart transmission system of mammals and the heart of crustaceans, and can cause contraction of small intestinal smooth muscle in rats. It is found that jellyfish toxin is tetramine complex, 5- hydroxytryptamine and polypeptide, which has strong histamine reaction. Its effects of dilating blood vessels and enhancing capillary permeability are 10 and 15 times that of 5- hydroxytryptamine respectively. It can also cause smooth muscle contraction or allergic reaction, leading to severe pulmonary edema and anaphylactic shock. After being stung by jellyfish, people have different symptoms due to different toxicity, toxins and individual sensitivity.

The thin and tender parts of human skin are most likely to be stung. It usually takes a few minutes to get an electric shock-like tingling. After a few hours, linear electric tingling will gradually appear in the injured area. After a few hours, the injured part will gradually appear linear blood rash with erythema, itchy and burning. Lighter ones can heal themselves in about 20 days. Patients with strong sensitivity may have erythema, edema, wheal, blisters, ecchymosis and even epidermal necrosis. The general manifestations of patients may include fidgeting, chills, abdominal pain, diarrhea, listlessness, chest tightness and shortness of breath. In severe cases, cough, asthma, vomiting of white or pink foam sputum, accompanied by signs of anaphylactic shock such as weak pulse, cyanosis of skin and decreased blood pressure. If the rescue is not timely, this stinger can die in a short time.

The most important thing to prevent jellyfish stings is to avoid contact with jellyfish, especially fishermen should do personal protection and not be careless. When fishing, use tools as much as possible, do not directly contact jellyfish whiskers, and prohibit people with specific sensitive physique from going to sea to work. During the jellyfish flood season, buoy fences should be set up in seaside tourist destinations, and eye-catching publicity and warning signs should be set up at the seaside to cooperate with the publicity and broadcasting of popular science education to prevent injuries and improve tourists' knowledge and ability of self-protection. People who swim or take a boat in the sea should never touch jellyfish, let alone catch them, because once an accident happens at sea, it is more difficult to rescue them. Once bitten by a jellyfish, the injured must not panic. As long as you go to the hospital for treatment in time, you will generally get better and recover quickly. On the other hand, if the stung person acts improperly or negligently, it is easy to drown and fall, or it will be dangerous and aggravate the condition due to the delay of treatment.

Jellyfish are extremely nutritious. According to the determination, every100g of jellyfish contains protein12.3g, carbohydrate 4g, calcium182mg, iodine132mg and various vitamins. Jellyfish is also a good medicine for treating diseases. Chinese medicine believes that jellyfish has the functions of clearing away heat and toxic materials, resolving phlegm and softening hardness, lowering blood pressure and reducing swelling. "Return to Yan Lu" said: "Sea snake is also a panacea, which can dispel qi and eliminate phlegm, diminish inflammation and eat it without hurting healthy qi. Therefore, asthma, chest pain, abdominal pain, fullness, constipation, leukorrhagia, malnutrition, jaundice and other symptoms can be eaten. " . The processed products are called jellyfish skin in the umbrella and jellyfish head in the wrist, and the commodity value of jellyfish skin is more expensive than jellyfish head.

As early as the Ming Dynasty, fishermen knew that fresh jellyfish were poisonous, so they had to marinate them with salt and alum, soak them to detoxify them, and filter out the water before eating them. However, from ancient times to the present, it is not uncommon for fishermen in the seaside of South Guangdong to eat fresh jellyfish poisoning by accident because they are greedy for delicious seafood. In addition, jellyfish, like other seafood, are easily contaminated by halophilic bacteria, and eating cold jellyfish silk by mistake can cause bacterial food poisoning. A bacterial food poisoning accident occurred in a hotel in Jiangmen City, Guangdong Province, where 73 people ate cold jellyfish.

Summer is the season when intestinal diseases are easy to occur and become popular. As a lesson from the past, raw jellyfish silk should be handled with care, and attention should be paid to hygiene during operation to prevent flies, dust and pollution. After shredding, it is best to rinse it repeatedly with cold boiled water and dry it to prevent food poisoning.

In China, jellyfish fishery has a long history, with a maximum annual output of 58,000 tons. However, due to reasons that are not fully understood so far, its resources change greatly every year, sometimes lying on the beach before processing, and sometimes nowhere to be found.

[Edit this paragraph] How to buy jellyfish

Alum is a dehydrating agent that must be used in the processing of jellyfish alum, but too much alum will lead to too high aluminum residue. The food standard requires that the content of alum in salted jellyfish is 1.2%-2.2%, and the proper proportion of alum can also ensure the taste, improve the quality and prolong the shelf life of the product. Fan Erhai jellyfish products sold by some manufacturers are not completely treated as finished products. The appearance of this jellyfish skin is translucent jelly-like, with soft and crisp white hemp rot. Squeeze gently with your hand and the liquid will overflow. Outside the head of this jellyfish.

It is brownish red, with a soft white jelly-like substance in the center, which is slippery and inedible.

In order to prevent jellyfish from rotting, borax and boric acid are often added as preservatives when processing jellyfish in hot climate areas. These two substances are food additives that are not allowed to be used by the state. Borax can cause poisoning symptoms, including nausea, vomiting, bloody dysentery and abdominal pain. Sulfite or sulfate, as a bleaching agent, is used by some jellyfish processing enterprises to remove the "head blood" and "red skin" of jellyfish, while sulfur dioxide can cause allergic reactions such as asthma, and some people may feel headache and nausea after ingesting this preservative. In view of these unsafe factors, China is implementing the quality standard of salted jellyfish.

High-quality jellyfish skin: it should be white or light yellow, shiny, natural and round, large and flat, without red, mottled and black spots, with thick and uniform meat and good toughness; No odor; Toughness; It tastes crisp and delicious.

Inferior jellyfish skin: the skin is deep and smelly, and the toughness is poor when rubbed by hand, which is easy to break.

High-quality jellyfish head: it should be white, yellow-brown or red-amber in natural color, shiny, complete in shape, without thorns, thick and tough meat and crisp in taste.

Inferior jellyfish head: purple-black, poor hand-kneading toughness, easy to break when held by hand, with peculiar smell and pus-like liquid.

In recent years, some manufacturers produce artificial jellyfish skin with alginate as raw material. Although the appearance of artificial jellyfish skin (silk) is similar to that of natural jellyfish skin, it has no nutritional components of natural jellyfish skin.

[Edit this paragraph] Practice

Vinegar stings:

Ingredients: jellyfish head 150g, leek powder 25g, soy sauce 15g, aged vinegar 30g, proper amount of sugar, monosodium glutamate 2g, sesame oil 10g, peanut oil 15g.

Practice: 1. Choose jellyfish marinated every other year, wash off the sediment, soak it in clear water for 5-6 hours, then wash off the sediment, cut it into small pieces along the jellyfish petals, and rinse it with clear water for several hours. 2. Put the chopped green onion in a small bowl, heat the peanut oil in a pot, and rush into the chopped green onion bowl to make the chopped green onion smell, that is, chopped green onion oil. 3. Filter the jellyfish head to remove water, enlarge the bowl, inject boiled water at 80℃, drain the boiled water immediately, add mature vinegar, soy sauce, sugar and monosodium glutamate while it is hot, and then pour in sesame oil and scallion oil to serve.