Electroencephalographic evidence for retention of olfactory cues in homing coho salmon.

Differences were observed in the magnitude of the evoked electroencephalographic response to 1 percent morpholine for homing coho salmon (Oncorhynchus kisutch) exposed to morpholine as fingerlings 1 month before smolting as compared to salmon not exposed to morpholine as fingerlings. These results indicate that olfactory information has been retained for 18 months, the period between smolting and the homeward migration.