In 2013, according to Yang Weilong, chairman of Suzhou Yangcheng Lake Hairy Crab Association, 180,000 acres(728sq km) of Yangcheng Lake was contracted to 1,000 qualified farmers.

The annual harvest of Yangcheng Lake hairy crabs hovers around 2,400 to 2,600 tons per year. National consumption each year, however, is more than 300,000 tons.

The math shows that real hairy crabs from the lake account for no more than 1 percent of the total sold.

In Shanghai alone, 300 tons of hairy crabs are eaten every day during the crab season. It means that the total harvest from Yangcheng Lake would be gone in just 8 days.

Most of the hairy crabs on the markets are "bath-tub crabs" or crabs from other areas masquerading as Yangcheng Lake originals.

The bath-tub crabs mainly come from Taihu Lake. Just before the official crab season starts, these crabs will be quietly transported to Yangcheng Lake and soaked in the lake waters for a week or two.

Some of the more unscrupulous vendors will even bleach the bellies of their crabs to meet the "snowy white" criteria.

A few years ago, the Suzhou Yangcheng Lake Hairy Crab Association started to tag its crabs. It took about a week before fake tags started selling on the Internet.

For the discerning consumer, any crab is a good crab if it is a healthy, naturally raised crustacean.

But of course there will be some who will insist on the designer label.