Abstract  Absorption, distribution, and release of squalane were studied in rainbow trout fed a diet containing 0.05% of this alkane. Estimated squalane absorption was about 40% of the dose. After three months of exposure, the residues in the whole body reached a steady equilibrium value of about 16- 18 micrograms/g. The most pronounced deposition occurred in the liver (1671 micrograms/g after 10 months), while the concentration of squalane in the adipose tissue was below 2 micrograms/g. During the depuration period, half of the contaminated trout were fed a squalane-free diet, while the others were starved. After two months, the body burden amounted to 65% and 80% of the alkane previously accumulated in starved and fed trout, respectively. In the starved group, 43% of the squalane initially stored in the liver was lost, whereas the loss in the fed fish liver was 52%. These results were compared with existing data on other alkanes. (Author 's abstract)