Oilfish is a common name for spiny snakehead mackerel and isosceles snakehead mackerel, commonly known as: spring fish, aliases include "round snow (cod) fish", "imitation snow (cod) fish", "white jade dolphin", "Butterfish" and so on. Oilfish belong to the mackerel family of fish, commonly found in the world's tropical and temperate oceans.

Wax esters contained in oil fish, although not toxic, but the human body is difficult to digest, and accumulated in the rectum, so some people eat, it will lead to diarrhea, gastrointestinal cramps and other discomforts, the oil may continue to flow from the anus. Patients will experience symptoms in as little as 30 minutes after eating, and most will recover within two days.

Also known as spring fish. The meat of the carp family, the anthropomorphic round-lipped fish [Semilabeoprocheilus (SauvageetDabry)]. The protozoa are found in the upper reaches of the Yangtze River and in the Minjiang, Tuojiang, Xijiang, and Qianjiang rivers. It can be used as medicine (see Yao Kecheng, Food Materia Medica). Sweet in flavor, flat in nature. Functions: tonifying qi, stopping bleeding. Mainly treats diarrhea and dysentery for a long time, vomiting blood, leakage and so on. Dosage 100-200g. Cooked, prepared with medicinal meals, such as "oil fish ginseng qi qi wai yao soup", "oil fish tonic soup" and so on.

There are more than 40% wax esters, because the wax esters solubility point is as high as 1000 ℃, the human body can not be decomposed and absorbed. Because of its fat content of more than 20%, and is used by the industry to extract oil, so it is called "oil fish.

Cod sold on the market are basically frozen slices, silver cod meat color white, meat above the particularly thick and obvious red line, fish scales are very dense, is a piece of the kind of pressure. Large cross-section is real cod, cross-section is small may be oil fish. This is because cod is larger than oilfish. Oilfish will have a yellowish or reddish line in the center, while cod does not.