The shrimp line of Macrobrachium nipponense is a part of the digestive tract. On the back, it is mostly dark brown, also known as "shrimp intestine". The shrimp line is sometimes black, sometimes white, and the white is the jejunum; Black is the undigested waste of shrimp, which will have a muddy smell and affect the taste. If shrimp is polluted, pollutants will also accumulate in the shrimp line, which will affect health. Whether it is black shrimp line or white shrimp line, it is necessary to remove the shrimp line before cooking.

Penaeus monodon, commonly known as sand shrimp and mud shrimp, belongs to crustacea, Decapoda, Penaeidae and Penaeus. Penaeus monodon is mainly distributed in the coastal areas of China, Fujian, Taiwan Province, Guangdong and Guangxi. Delicious taste and high economic value. Because of its strong tolerance to low salt, high water temperature and low dissolved oxygen, Penaeus monodon can survive for a long time after leaving water, which is suitable for commercial culture.