Only highly skilled chefs can prepare these fish so they can be served safely to diners. News of fishermen getting poisoned after eating the fish has frequently been reported in China.

Until recently pufferfish, which is also known by its Japanese name, fugu, was offered at high-end private clubs on the sly – because there was a ban on serving it. The reason for the recent proliferation of pufferfish restaurants in Beijing is that Chinese fish farmers have succeeded in breeding non-poisonous varieties, which allowed the Chinese government to lift the ban.

Before it was lifted in 2016, some restaurants were allowed to operate on a trial basis, among them April Puffer. The Chinese government allowed this so it could collect data on pufferfish dining.

April Puffer board chairman and founder Duan Ran, a former researcher with the ministry of agriculture, says it opened two restaurants in 2014 to test market response to the fish.

Duan says before he was able to open April Puffer, he had to explain to Beijing city officials that there was a trial going on at the national level to test the safest methods of raising pufferfish and to make them non-poisonous.

The agriculture ministry set up a pufferfish safety research team in 1993 to develop poison-free pufferfish species.

Duan, whose company operates two fisheries in eastern China, says the fish are poisonous because of their diet. “With sharp teeth, they feed on little shrimps and crustaceans which have green algae on them. The puffer’s [internal systems] will turn the algae into a neurotoxin which can kill humans in an instant. So wild pufferfish are very dangerous.

“In our fisheries, we don’t let the fish come into contact with those creatures [carrying algae]. Before setting up a fishery in shallow water, we will first clear the seabed. Those residing in tanks are also free of those creatures,” he says.

There are more than 100 pufferfish species in the world, but only two species – Takifugu rubripes, known as tiger pufferfish, and Takifugu obscurus – are allowed to be raised in fisheries in China.

“The raising of these two species is a very mature [industry] in China, with Takifugu rubripes in its seventh generation and Takifugu obscurus in more than its 10th generation. Fish with poison-generating DNA are bred out generation after generation. So the pufferfish produced in China’s fisheries cannot generate poison any more,” Duan says.

“Before the lifting of the ban in 2016, the pufferfish industry was sealed off, with the industry dominated by fisheries [like my own] exporting the fish to East Asia,” he says.

April Puffer now has nine restaurants in Beijing and one in Jiangxi province, eastern China, with two more to open in Shenzhen and Guangzhou, in southern Guangdong province.

Another restaurant chain, Tianzheng Puffer, served pufferfish back in 2003 in a restaurant in Dalian in China’s northeast, where early Chinese government trials of pufferfish dining were held, says its technical director, Wang Chengtao.

The company operates five fisheries, which it says supply 60 per cent of the pufferfish eaten in Japan, and has five restaurants in Beijing.

Wang says that, while China allows diners to eat only two species of pufferfish, more than 20 species are popular in restaurants in Japan.

“Japan’s puffer supply is not enough to satisfy local consumption. So they import most of them from China. We feed our puffers only sand eels, which are abundant in northern China. The Japanese only import the Takifugu rubripes from us, which is a saltwater fish. They rarely use Takifugu obscurus, which is a freshwater species,” he says.

Japan, which is famed for its meticulous and extremely expensive preparation of poisonous pufferfish, requires chefs to take a rigorous exam and gain accreditation before they are licensed to serve fugu. But chefs in China do not need to undergo as much training, as the pufferfish is already poison-free when it leaves the fisheries.

Wang says training for Chinese pufferfish chefs focuses on species identification and cooking skills.

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“If they can’t distinguish between the species, poisonings can easily happen,” he says. “For cooking, Takifugu rubripes is [used in] both Japanese- and Chinese-style dishes, while Takifugu obscurus is only used for Chinese dishes.

“For Japanese dishes, chefs cut the fish into different parts [which are prepared using] different cooking methods. No part of the fish is wasted. Even the skin is used for salads, after the bristles are removed. Chefs have to learn how to make thin and even slices [of the flesh] for sashimi.

“For Chinese cooking, the whole fish is braised or served in a soup. Diners have to be told to turn the fish over when eating so the bristle-laden skin is not consumed. The puffer’s muscles are tight, so it tastes a bit hard and chewy. Chefs have to learn how to make the flesh soft and tasty.”

Duan, who earned bachelor’s and master’s degrees in biology from Lanzhou University and a doctorate in agricultural environmental studies from the Chinese Academy of Agricultural Sciences, says he invented a dish called puffer fotiaoqiang, a luxurious casserole, which was patented.

Wang says poison-free pufferfish are delivered frozen to restaurants or supermarkets in China, with no live sales allowed.

“The pufferfish swimming in tanks in Chinese restaurants are for decoration only. The pufferfish you can buy in the market is perfectly safe. All the poison-removing processes are done in the fisheries. The government only need monitor the fisheries, instead of individual chefs.

“Each fish has a bar code which, after scanning, can be traced to its fishery and processing unit.”

While Japan is the country most famous for fugu, Wang and Duan say that the custom of eating pufferfish originated in China, where it’s been consumed for thousands of years.

Duan says the Chinese have been eating pufferfish since the reign of Emperor Yu the Great (2205-2197BC). “Pufferfish was considered a precious delicacy. It was featured in imperial menus as early as the Tang dynasty [AD618-907],” he says.

Duan notes that Japan legalised the consumption of pufferfish in the early 20th century, but that it took China a lot longer. “China started the process in 1993, but it was finished only 20 years later.”

Wang says: “Chinese [people] have risked death to eat pufferfish for a long time. The government couldn’t inspect every household to implement the pufferfish ban. So it opened up the industry by legalising it.”

Duan says that, thanks to the legalisation, and to the number of fisheries experts graduating from the Ocean University of China and Dalian Ocean University, “pufferfish dining will soon become hugely popular like the eating of crayfish”.

April Puffer is also developing pufferfish tonics. “Its skin has a tonic effect like swallow’s nest and ginseng,” he says.