The Sea of Japan continental slope food web was examined by analysis of stable C and N isotopes and fatty acid compositions in ten species of common benthic organisms and in sediment and particulate organic matter. A considerable range of δ 13 C and δ 15 N values was found for benthic species, with δ 13 C values of −22.3‰ in crinoids ( Heliometra glacialis ) to −16.1‰ in asteroids ( Ctenodiscus crispatus ) and with δ 15 N values of 5.3‰ in foraminifera ( Elphidium sp.) to 15.5‰ in C. crispatus. Polyunsaturated fatty acids were the most abundant of the fatty acids in the total lipids of all investigated species. The organisms’ individual fatty acid compositions show the importance of a variety of food sources, including phytoplankton, detritus, foraminiferans and zooplankton, for megabenthic species. Additionally, the presence of considerable amounts of the 20:4( n -6) and 20:1( n -13) fatty acids indicates the importance of the benthic microbial loop in the nutrition of some of the studied animals.