Tears in food!Why is the hairy crabs "thin" this autumn?

The autumn wind is itchy, and it is time to eat crab for another year.

But sorry, this year's fall, hairy crabs may disappoint you--

"High temperature hungry hairy crabs", "hairy crabs will work harder to be absent from Mid -Autumn Festival" ... What is going on?

01

What are the effects of high temperature on hairy crabs?

The official name of hairy crabs is "ErioCheir Sinensis", which are distributed in many river lakes in my country.

There is a saying about the origin of the name of "hairy crab". There was a saying that after the fishermen caught this crab, they would be boiled directly with water. This kind of cooking method in Wu language was called "煠 (zhá)", so it was called "crab". Later During the circulation process, it became "hairy crabs".

Another saying is that before the crab catcher must be built with bamboo branches and straw, the net on one side of the gate, the horse lights are on at night, the crab group is seduced in the lake, and the gate is trapped. So it is called "hairy crab".

Gallery copyright picture, not authorized reprint

Hairy crabs can survive within the temperature range of 5 ° C-30 ° C. The most suitable temperature is 20 ° C-25 ° C. When the temperature is higher than 30 ° C, hairy crabs will have symptoms such as anorexia, soft joints, weak exercise, and slow growth. If the temperature is higher than 35 ° C, they can hardly eat, only consume the original energy in the body, and do not have the strength to molt. However, for hairy crabs, limb animals need to be faded 5 times in the growth cycle to achieve the best body type of consumption.

In the natural environment, animals will find ways to avoid poor weather to reduce the impact of its impact on itself, such as going to the deep water area, or hiding in the mud from the bottom of the river to avoid high temperature, but the hairy crabs we eat are almost almost the hairy crabs, almost almost the hairy crabs, almost almost the hairy crabs, almost almost the hairy crabs, almost almost the hairy crabs, almost almost the hairy crabs, almost almost the hairy crabs, almost almost the hairy crabs, almost almost the hairy crabs, almost almost the hairy crabs. Most of them are artificially cultivated, and most of the crab ponds are cement ponds, it is difficult to "avoid summer" by transferring or digging holes.

After understanding the habits of hairy crabs, and comparing Hubei, Hunan, Jiangsu and other places, which are the main hairy crabs, they have exceeded 40 ° C this summer, it is not difficult to understand why they "shrink" this year, and the listing time is postponed.

This summer (June 1st to August 31st) national average temperature of 22.3 ° C, 1.1 ° C higher than the same period of the year

It was the highest history since 1961 with a complete meteorological observation record. Picture source: Weibo@图片 weather weather

Extremely high temperature daily distribution in the country. Picture source: Weibo@图片 weather weather

Excessive temperature will not only affect the hairy crabs itself, but also their living environment.

The aquatic plants in the crab pond are not only a feed for hairy crabs, but also can be shaded and purified the quality of the hairy crabs.

At the same time, high temperatures can easily increase the number of floats in water, and the impact of large water bodies may not be obvious. Oxygen consumption in water causes hypoxia in the water, affects the growth of hairy crabs, and severely causes hairy crabs to die.

Furthermore, hairy crabs are very afraid of heat during transportation. If you observe it carefully, you will find that mailing crabs will use plastic foam insulation boxes. A few ice packs should be added to keep the temperature and humidity in the box during transportation to avoid crabs from crabs die. Continuous high temperature weather also increases the loss of hairy crabs during transportation.

Yangcheng Lake hairy crab pond. Gallery copyright picture, not authorized reprint

Of course, rising temperature is not the only reason for the changes in the hairy crab market. Another important reason is that this year's southern precipitation is also small.

The decrease in high temperature and rainwater has made many lakes and rivers less water, and the area of ​​water body decreases significantly. For example, the water level in some areas of Dongting Lake has reached the lowest history of the same period, which is 7.82 meters. The area of ​​the water body of the Tongjiang River in Poyang Lake has shrunk by nearly 90 % from the same period last year, and other waters in the middle and lower reaches of the Yangtze River have a great impact.

In this case, the water surface that can provide hairy crabs will be reduced, and the reduction of hairy crab output has become the result of the nail on the board.

This year's Yangtze River Basin (358.9 mm) precipitation is 32.5%less than the same period of the same year. It is the least in history since 1961.

Taihu Basin (296.8 mm) has less than 47.3%less than the same period of the same year, the fourth less in history.

Picture source: Weibo@图片 weather weather

This year's high temperature also affects sea crabs.

Common sea crabs include three warts, crab crabs, distant barracuda crabs, red -star barracuda crabs, Japanese pupae, rusty spots, and so on. Unlike hairy crabs, these sea crabs are mainly from fishing. They are currently fishing for less than 80% of last year in Zhoushan, Shengsi and other regions, and the quality is not as good as the same period last year.

High temperature also increased the loss of these sea crabs during transportation, which further raised the "crab price".

02

How can I pick up delicious hairy crabs?

Facing the price of hairy crabs this year, it is: "Hairy crabs, it's not easy to say love you."

But if you still want to be full, how can you "crab fortune"? It is important to master the choice of hairy crabs.

We know that the deliciousness of hairy crabs, except for crab meat, mainly comes from "crab yellow" and "crab paste". The "crab yellow" of the mother crab is orange -yellow liver pancreatic and orange gland (ovarian), and the "yellow" of male crabs is liver pancreatic. "Crab Ointment" is a side glands.

Gallery copyright picture, not authorized reprint

There are two important indicators that affect the flavor of hairy crabs: fullness and sweetness.

Popularly speaking, fullness refers to the amount of meat and yellow, while sweetness is the flavor of meat and yellow. High -quality hairy crabs, yellow and ointment have a sweet taste of sweetness, and the bad quality crabs will taste salty or bitter.

The fullness of hairy crabs can be guaranteed by eating sufficient plant feed, but the sweetness must be supplemented by animal bait.

In order to ensure the taste of hairy crabs this year, the impact of the temperature was minimized, and the crab farmers also tried their best:

For example, planting reeds, wheels black algae, Iraza, bitter grass and other aquatic plants in the crab pond. Plants can reduce the temperature of the water body of the pond in the pond and provide shading and avoiding places for hairy crabs. By strengthening the circulation of the crab pond water body, the temperature of the water body in the crab pond is reduced, the oxygen agemchomor is installed, and the oxygen content of the water in the crab pond is increased by stirring and promoting the water circulation.

After such a "toss", the state of hairy crabs in the pond will improve.

Gallery copyright picture, not authorized reprint

Before hairy crabs are listed, the crab farmers will also ensure the sweetness of hairy crabs by feeding a large amount of animal bait such as fish and shrimp.

Here is to share with you a way to pick hairy crabs--

There are four major characteristics of hairy crabs:

The first is the blue back, the crab shell is green, smooth and shiny;

The second is a white belly, with a dull umbilical belly shell, crystal clear and white;

Third, yellow hair, the hair of the crab legs is yellow and yellow, the root is straight;

Fourth, golden claws, golden crab claws, solid and powerful.

If the crab is in your hand, it must be heavy, so such crabs will be full. You can also turn the crabs without tie rope. The belly is facing up. If the crab can quickly turn over and flexible, it means that the crab is strong and fresh.

The continuous high temperature will indeed bring us a lot of trouble to eating crabs. However, some meteorologists believe that continuous high temperatures like this year will not become the norm. Maybe we can continue to eat crabs happily next year.

Of course, in order to be able to eat the fat and cheap "good crabs", each of us also gives our own strength to protect the environment as much as possible.

Author ｜ Erzhu

Review ｜ Chen Shengjun Institute of Aquatic Research Institute of Nanhai Aquatic Aquatic Products in China

Reprinted content only represents the author's point of view

Does not represent the position of the Institute of Physics of the Chinese Academy of Sciences

If you need to reprint, please contact the original public account

Source: Science Popularization China

Edit: Paarthurnax

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