"We would select the best male and female crabs to breed, then choose the offspring that merited further breeding. After breeding several generations of crabs, we finally created a species that has a green shell, white belly, golden legs and yellow hair," says Wang, who has partnered with several crab farms, including Huang's Baodao Crab Farm, on Chongming Island, to perform large-scale experimentation.

In 2016, Wang's effort was recognized by the government as the Jianghai 21 variant gained approval of the then Ministry of Agriculture (now Ministry of Agriculture and Rural Affairs) for classification as a national "merit aquatic product breed".

"The new breed is bigger and grows faster, and following improvements in crab-farming, 70 percent of the female crabs now weigh more than 150 grams, while male crabs weigh more than 200 grams," Wang says.

Today, the price of a single hairy crab from Chongming Island ranges from 30 yuan ($4.5) to 200 yuan, a stark contrast to the past when it was sold for 10 or 20 yuan, says Huang.

The thriving industry has been a boon for Huang's business as well. His Baodao Crab Farm currently spans 46 hectares, up from the 26-hectare operation he started with, and generates about 75,000 kilograms of crabs every year.