A comparative chemical study on population-specific odorants from atlantic salmon

Samples of skin mucus and intestinal contents were collected from groups of salmon presmolt from three Norwegian rivers. The supernatants obtained after precipitation were gel-filtered on a Sephadex G-25 column, which revealed peaks with absorption at 280 nm. Fractions incorporating a group of retarded peaks were examined by two-dimensional thin-layer chromatography. The spots obtained on the thin-layer plates were sorted out by means of position, intensity, and fluorescence properties.R f values for the assumed identical spots from each group were subjected to statistical analysis. In one of the chromatography systems, 8 spots of 24 from samples of skin mucus and 6 spots of 27 from intestinal contents show larger standard deviations (SD) ofR f than may be expected when a substance is chromatographed repeatedly. These SDs fit a linear relationship of SD to chromatography length by a probability of less than 0.01. The results indicate a molecular variation between the groups which could be a source for population-specific odorants. If these substances are used in chemical communication, they can provide the specific clues needed for a successful return to the home river.