The lipid composition of the various tissues (muscle, intestine, pyloric caecum, liver, heart, kidney, ovary and intestinal content) of Lepidocybium flavobrunneum (of Acinaceidae=Gempyridae, termed "Aburasokomutsu" in Japanese, and known as one of the fish containing large amounts of wax esters in the muscle lipid) was examined.The muscle, pyloric caecum and liver contained large amounts of lipid. The lipids of muscle, pyloric caecum, intestine and intestinal content contained large amounts of unsaponifiable matter (high unsap. tissue), whereas lipids of the heart, kidney, ovary and liver contained only small amounts (low unsap. tissue). In particular, liver lipid contained only 3.5%. The lipid of high unsap. tissue was predominantly wax esters and the unsaponifiable matter was fatty alcohols. The specific distribution of wax esters was shown among various tissues. The 18 : 1 fatty acid was the major fatty acid component in wax ester fraction of various tissues, but 16 : 0 and 22 : 6 fatty acids amounted to a comparable percentage of 18 : 1 fatty acid in the other lipid fraction. The 16 : 0 and 18 : 1 fatty alcohols were the main fatty alcohol components in wax ester and free fractions. The lipid of low unsap. tissue (especially liver) contained large amounts of free fatty acid, which was supposed to be formed by hydrolysis of triglycerides during storage in a freezer. 1 Introduction Lipids are generally stored in fish in the form of triglycerides. However, some fish con•¬ tain predominantly nontriglyceride-lipids such as wax esters or diacylglyceryl ethers. These lipids are hard to digest or absorbed by mammals including man; they cause diarrhea when consumed in large amounts1)•`3). By law the Japanese Ministry of Health prohibits the sale of Ruvettus pretiosus ("Baramutsu" in Japanese) and Lepidocybium liavobrunneum

The muscle of rudder fish (one of the deep-sea fishes, Centrolophus niger: Stromateidae) contained a large amount of lipid which showed an extremely higher value for unsaponifiable matter contents and lower saponification value than of other fishes. Moreover the lipid showed very low triglyceride contents.The trimethylsilyl derivatives of unsaponifiable matters were analyzed by the methods of gas-liquid chromatography and mass spectrometry. These results assured that the unsaponifiable matters had the 1, 2-diol structure, and were presumed to be glyceryl ethers.We also investigated about the muscle lipids of some deep-sea fishes (silver king fish: Rexea solandri, silver fish: Sriollela punctata, Black cod: Anopiopoma fimbria).The triglyceride was the major constituent of their muscle lipids. Among them, silver king fish had the lowest saponification value and the highest contents for unsaponifiable matters which showed the same properties as that of rudder fish.