The price of hairy crabs has dropped! Will we finally have the freedom to eat crabs?

It’s crab time again. For all you “crab lovers”, this year there is good news that will make both your stomach and your wallet happy: media in many places reported that the price of hairy crabs has dropped!

The picture comes from the Internet

One netizen said: "I bought eight 3.5 liang female crabs for just over 200 yuan. In previous years, crabs this big would have cost around 300 yuan."

Not only has the price dropped, the size of hairy crabs has also increased this year. On e-commerce platforms, the mainstream products last year were still crabs weighing 200 to 300 grams, but this year the main products are crabs weighing 300 to 400 grams.

Why are hairy crabs, which used to be expensive, now cheaper? Are we finally going to have the freedom to eat crabs?

What kind of crab is the hairy crab?

There are more than 6,500 species of marine and freshwater crabs in the world that can be called "crabs", but the most common and most consumed one on the market is the hairy crab, whose official Chinese name is "Chinese mitten crab" (Eriocheirsinensis).

One of the signs to identify hairy crabs is their hairy claws. Image source: Wikipedia

There are two theories about the origin of the name "hairy crab":

One theory is that the tool used to catch crabs is called a "gate", which is a straw mat supported by a frame with an oil lamp on top. Crabs are attracted to light and will climb up the frame along the mat when they are active at night, giving fishermen the opportunity to catch them.

Another theory is that fishermen would boil these crabs directly in water after catching them. In Wu dialect, this cooking method is called "煠(zhá)", so it is called "煠蟹". Later, it evolved into "闸蟹" during the process of transmission.

The most suitable growth temperature for hairy crabs is between 20 and 25 degrees Celsius. If problems occur during the breeding process, it is likely to cause the hairy crabs to become diseased, grow slowly, or even die in large numbers.

For example, the long-term high temperature last year led to a reduction in the production of hairy crabs in many production areas, causing the price to rise all the way (you can review the previous article "Foodies are crying! Why are hairy crabs so thin during the Mid-Autumn Festival this year?")

Why are hairy crabs so cheap this year?

1

Changes in farming methods

Crab farmers who experienced the extreme climate last year have begun to work hard on their breeding methods. Wild hairy crabs can dig holes to create their own "shelters" to escape the heat when encountering high temperatures. Crab farmers have added sunshade facilities to crab ponds to reduce the temperature in crab ponds; added aquatic plants such as reeds, elodea, and Vallisneria in crab ponds, which can provide a hiding place for hairy crabs and provide shade for them, while also improving water quality; strengthened water circulation in crab ponds to reduce the water temperature in crab ponds; installed an aeration system to increase the oxygen content in the water in crab ponds to prevent hairy crabs from hypoxia due to high temperatures. Through various methods, the production of hairy crabs this year has been preserved.

2

The number of hairy crab production areas has increased

Agricultural workers are also actively developing new hairy crab producing areas. The most famous hairy crab producing area is Yangcheng Lake. Jiangsu also has many other famous hairy crab producing areas such as Gucheng Lake and Taihu Lake. However, in recent years, Hubei hairy crabs have become more and more famous. Not only is the area of ​​crab ponds increasing, but with the improvement of breeding technology, the quality of hairy crabs from many producing areas is not inferior to that of Jiangsu.

In addition, Xinjiang's "snow crab" has also become very popular this year. The breeding area has now reached more than 20,000 acres, and the output can reach 100 tons, which will triple in the future.

Image source: pixabay

With the emergence of more and more high-quality hairy crab producing areas, the price of hairy crabs will definitely become cheaper and cheaper.

How to choose good quality hairy crabs?

1. Observe whether the crab shell is clean. Generally, the shells of crabs raised in clean water will be cleaner and free of silt, while crabs raised in turbid water will generally have a heavier "earthy smell".

2. Weigh the hairy crab with your hand. The crab should feel heavy in your hand, which means it is fuller. If it feels light, it probably has little meat and will be an empty shell after being cooked.

3. Observe the vitality of the crab. Hairy crabs must be eaten fresh. After the hairy crab dies, a large number of bacteria will quickly grow in the body tissues, thus producing toxins. These toxins will not be decomposed by the high temperature of cooking, and will cause food poisoning after consumption. You can let the hairy crab face up. If it can turn over quickly, it means it is full of vitality. If the hairy crab is tied, you can touch its eyes lightly. If it can retract quickly, it means it is very fresh. If it does not move, it is likely dead.

Which parts of hairy crab are eaten?

Although we eat the meat of hairy crabs, what we mainly eat are the "crab roe" and "crab paste".

"Crab roe" is the orange-yellow hepatopancreas and orange gonads (ovaries) of female crabs. The roe of male crabs is also from the hepatopancreas, and the crab paste is the accessory gonads of male crabs.

The outstanding features of crab roe are high protein and high fat, among which the protein content is as high as 24% and the fat is 17.2%, so it tastes very delicious. It is worth mentioning that more than 2/3 of the fatty acid composition is relatively healthy unsaturated fatty acids.

When eating crab roe, you may find that there is a layer of black film on the outside of it. Don’t worry about whether it is "dirty stuff". It is mainly collagen and can be eaten.

Image source: provided by the author

There are also some parts of hairy crabs that are not recommended for eating:

Crab intestines

There was crab excrement in it.

Image source: Bilibili @Miao Zhao Jie

Crab gills

The crab's respiratory organs are used to filter water, and some pollutants will stick to them.

Photo taken by: Qingshan Wuchai

Crab stomach

It contains the food that the crab eats, which may contain mud and sand.

Image source: Bilibili @Miao Zhao Jie

Regarding crab heart, there is no evidence that it cannot be eaten. It is mainly a matter of taste. If you have eaten it before and did not feel uncomfortable, it is fine. Having said so much, why not have some hairy crabs to satisfy your cravings~

References

[1] Lin Yi, Chen Ling. High-quality, efficient and pollution-free breeding methods for hairy crabs[J]. Agricultural Science and Technology, 2006(03):28-29.

[2] Liu Bo, Zhou Qunlan, Jiang Guochun, et al. Study on the effects of several common oxygenation methods on the water quality of crab breeding ponds [C]//2009 Jiangsu Fisheries Academic Annual Conference and Academic Seminar. Jiangsu Fisheries Society, 2009.

[3] Yang Yuexin. "Chinese Food Composition Table Standard Edition" 6th Edition Volume 2 [M]. Beijing: Peking University Medical Press, 2019.

Author: Erzhu Popular Science Creator

Review｜Liu Yadan, Researcher of Chinese Society of Fisheries