Evidence for celestial and magnetic compass orientation in lake migrating sockeye salmon fry
- Cite this article as:
- Quinn, T.P. J. Comp. Physiol. (1980) 137: 243. doi:10.1007/BF00657119
- 353 Downloads
Radially symmetrical, four-armed tanks were designed for testing the directional preferences of sockeye salmon (Oncorhynchus nerka) fry as they commenced up-lake migrations following emergence from gravel nests and river migration to the lake.
When tested during the day or night, as appropriate for their migration, fry from two different stocks moved in compass directions corresponding to the directions which they would have to maintain in their up-lake migration.
The directional preferences of one population tested during the non-migratory time of day apparently corresponded to the fry's onshore movement.
Orientation was maintained under both overcast and clear skies, and under plastic covers as well. A 90° counter-clockwise shift in the horizontal component of the earth's magnetic field was associated with approximately 90° changes in the mean direction of movement of fry at night, even when they were given a view of the sky. During the day, only fish tested in covered tanks displayed redirected movements in the altered field; those tested with a view of the sky showed geographically appropriate movement patterns despite the shifted field.