Perception of Polarized Light by Yearling Sockeye Salmon (Oncorhynchus nerka)

Abstract

Food-conditioning experiments conducted in the laboratory demonstrated that groups of yearling sockeye salmon (Oncorhynchus nerka) can discriminate between vertical and horizontal planes of linearly polarized light. Removal of the adipose eyelid, a possible analyser of polarized light, did not abolish the response. The findings support the hypothesis that these fish can use polarization patterns for orientation during their seaward migration.