The fatty acid composition of body oil extracted from lamprey, Entosphenus japonicas Martens, in spring (Apr.May) and autumn (Aug.Dec.) was determined by GLC and GC-MS.
1) The major (>10%) n-3 fatty acids of lamprey body oil were C20 : 5 and C22 : 6.
2) The ratio of fatty acids, C14 : 0/C16 : 0/C16 : 1/C18 : 1/C20 : 5/C22 : 6 in lamprey body oil was approximately 1 : 2 : 2 : 3.8 : 2 : 2.