Why China is crazy for crayfish

Over the past few years, China has found itself in the grip - or should that be the claws - of a new food fad: the crayfish.

Crayfish restaurants and crayfish farms are booming.

State media says consumption in the city of Nanjing of the little freshwater crustaceans has soared by 20% a year.

For the latest in our Taste of Asia series, we hear from two sisters in Shanghai - another city that's gone crayfish crazy.