Tubo fish is a common name, and its scientific name should be "Tangyan fish". Once widely lived in tropical and subtropical seawater and fresh water. The Yangtze River basin belongs to the temperate zone, but before1980s, there were rivers and inland ponds in the south of the Yangtze River.

The popularity of Tubo fish is also related to the World Expo. The night before the opening of the Shanghai World Expo, a grand state banquet was held at the Shanghai International Convention Center, which was called "the first banquet of the World Expo". One of the main courses of dinner is shepherd's purse and snapper. At present, many hotels in Jiangsu and Zhejiang have begun to write black fish in shepherd's purse pond as a typical spring delicacy in Jiangnan. The market demand for loach (that is, indigenous fish) is increasing gradually.