HONG KONG — At hotpot restaurants in China, most of the ingredients are relatively inexpensive. Customers dip pieces of raw meat and vegetables into a big vat of simmering broth until everything cooks and bubbles to the surface.

For one Chinese restaurant chain, however, an item found by a customer at one of its outlets has proved to be particularly costly: a rat.

A video of a small, dead rat — boiled, gelatinous and with its stunned arms outstretched — fished out of a vat of bubbling broth has shocked China, and sent shares of a popular restaurant chain plummeting.

The rat was found last week at a branch of the chain, Xiabu Xiabu, in Weifang, a city in the eastern province of Shandong. A local newspaper reported the incident on Friday and video footage of the customer picking the rat out with chopsticks circulated on Chinese social media all weekend.