The so-called “Kuroko-zame” which is caught off the coast of Sanriku consists at least of the two species, Nagahera-zame in Japanese, Apristurus macrorhynchus, and Kasumi-zame in Japanese, Centroscyllium ritteri. The shark liver oils were extracted from the two kinds of sharks which were biologically measured, and their properties and lipid class composition were compared.
1) Even from the specific gravity (d_??_) and the refractive index (n_??_) the two liver oils were characterized each other. The latter one (0.8845) was lighter than the former (0.9096) in the specific gravity, and the former (1.4703) was slightly smaller than the latter (1.4778) in the refractive index.
2) There was found great individual difference among the specimen used, however, the former liver oils contained a little unsaponifiable materials (less than 13%) and the latter reached to over 50%. The content of the hydrocarbons which consisted of squalene as the major component and pristane as minor was up to 3% in the former liver oils and less than 42% in the latter.
3) As to the lipid class composition of the unsaponifiable materials, the former one contains a large amounts of the glyceryl ethers with the hydrocarbons and relatively high content of cholesterol, whereas the latter consists of the hydrocarbons as the major component with the glyceryl ethers and a little cholesteol.
4) The glyceryl ether and fatty acid composition showed rather similar patterns.
These results except the article 4 recommend the discriminating treatment between the Apristurus and Centroscyllium liver oils without identifying them as a “Kuroko-zame” liver oil.