Squid is one of the nicknames of squid. It is a class of teleost and flounder, and also a kind of flounder. The body is flat and asymmetrical, and both eyes are on the left. In front of the mouth, the jaw protrudes. The edge of the anterior branchial lid is free. Skin with eyes is dark gray or patchy, and skin without eyes is white. There are many kinds of catfish, widely distributed in tropical or temperate oceans. There is also a large amount of production in China's coastal areas. Mainly used for fresh food or canned and pickled products. Fish liver can be used to extract cod liver oil. In particular, PARALICHTHYS olivaceus is a rare fish in the Yellow Sea and Bohai Sea in China. Like other flounder species, it is a famous dish with seasonal flavor.

Opium fish head contains more calcium, phosphorus, iron, vitamin B 1, purine, monophosphate and unsaturated fatty acids than any other food. Fish head epidermis is also rich in collagen; In addition, the gold content of its brain is 36 times that of ordinary fish head, which plays an extremely important role in softening blood vessels, reducing blood fat, strengthening the brain and delaying aging.