It is a challenging job to distinguish where hairy crabs come from, especially when they are packed. Gao Erqiang / For China Daily

Yangcheng Lake became famous for these seasonal delicacies, and every year from September to November. the lake district turns into a culinary mecca for hairy crab lovers.

It also changed the lives of Yangcheng Lake farmers and fishermen.

In no more than 10 years, the voracious crowds had eaten the crabs almost out of existence, and farms could no longer supply growing demand with truly local crabs.

To keep a good thing going, farmers started bringing in stock from other parts of the Jiangsu-Zhejiang area, including baby crabs caught off Chongming Island in Shanghai, and the greater Taihu Lake area.

Zhang Dawei, 50, is currently a cab driver in Shanghai, but his family still breeds hairy crabs on Chongming Island in the rural suburbs of the municipality where they have a two-hectare farm.

"We used to go out and catch baby crabs around late March and early April. We would sell them to the Yangcheng Lake farmers for 8 yuan each. That was about 10 years ago," Zhang remembers.

The golden era ended when the government set up a research farm in Zhejiang that concentrated on breeding hairy crabs and selling baby stock to farmers for only about 3 yuan apiece.

"There are no more real Yangcheng Lake hairy crabs. It's too expensive to rent a raft of cages there," Zhang explains.