大闸蟹 (Dazha crab), or more widely known as Shanghai Hairy Crab, is in season right now. This typical Shanghai delicacy is particularly sought after for its rich and creamy roe, in fact, I never eat its meat, the meat is scarce and just too ordinary compared to its roe.
Hairy crabs ready for serving: so yummy and yet so bad for your health.......
However, like, well, most things from China if not all, hairy crabs suffer problems with the fakes. Although most hairy crabs on the market are claimed to be the genuine Yangcheng Lake hairy crabs, some insiders have revealed that probably 99% of them are fakes from other lakes. One old trick is to dunk these less priced crabs into Yangcheng Lake just prior to the crab season, then viola, you've got "Yangcheng Hairy Crabs" to sell.
To give consumers confidence, there have been different measures used to guarantee the quality of the crabs. Some crabs have logos laser-engraved on the back; some wear a special ring on one of the claws. However, most businessmen are quick to get around these barriers. You can have an ordinary crab engraved with a "Yangcheng Lake" logo for 30 cents RMB, and the special IC embedded crab rings can be taken off and put on other crabs. Some of the rings are sold to unknown crab traders.
A laser-engraved hairy crab
The price may give you a little more reference: those eight-dollar ones in the wet market are highly probably fakes, however, that is not to say those 400-dollar ones in a restaurant are definitely genuine. If it's too big (eg, over 200 grams), it's probably a fake, too.
The special chip-embedded ID ring
If you are not too concerned about the fakes, there is still the problem with the possible carcinogens. In fact, some of the crabs exported to Taiwan last year were found to contain nitrofuran, a banned antibiotics and a suspected carcinogen.