Comparison of mucus collecting methods in fish olfaction.

A new method for collecting non-contaminated skin mucus from fishes is introduced. The method is compared with a "customary" method by gel filtration, analysis of free amino acids, and determination of dry weight. Skin mucus collected by the "customary" method is shown to be contaminated by intestinal juice. The role of skin mucus as a source of fish odorants affecting fish behaviour is discussed in the light of the above findings.