In 5 holothurian species of the Aspidochirota and Elasipoda orders concentration of organic carbon in alimentary canals due to selective feeding on the average is 7 times higher than in host sediments. Concentration decreases from the first section of the alimentary canal to the last. Intestinal contents are enriched with bitumens, in which amount of oils and resins increases, while that of asphaltenes slightly decreases from the first section to the last. It is conjectured from analysis of structure and group composition of oil fraction of bitumens that heteroatomic and specifically oxygen-containing rather than purely hydrocarbon compounds have food value. Organic matter in intestines contains 6 to 9 kcal/g. Judging by changes in chemical composition of contents, only a few of these calories are utilized. Hence to assure themselves of energy they need, organisms must continuously pass sedimentary material through their alimentary canals.

Supplement to: Bordovsky, Oleg K; Sokolova, Maria N; Smirnov, B A; Akhmet'yeva, E A; Zezina, Olga N (1974): Evaluation of the role of bottom fauna in the transformation of organic matter in sediments (with specific reference to the deep-sea detritus-feeders in the Kuril-Kamchatka Trench). Oceanology, 14, 128-132