Fate of a hydrocarbon pollution indicator in fish: Absorption, deposition and depuration of squalane in Salmo gairdneri R.

Absorption, distribution and release of squalane were studied in rainbow trout fed a diet containing 0·05% of this alkane.

Whether faeces were collected automatically from pond water or by manual stripping, the estimated squalone absorption was ca. 40% of the dose.

After 3 months of exposure, the residues in the whole body reached a steady equilibrium value in the 16–18 μg g⁻¹ range. The most pronounced deposition occurred in the liver (1671 μg g⁻¹ after 10 months) while the concentration of squalane in the adipose tissue was below 2 μg g⁻¹.

During the depuration period, half of the contaminated trout were fed a squalane-free diet, while the others were starved. After 2 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 data regarding other alkanes previously investigated.