|SREL Reprint #0637|
Sun Compass Orientation of Immature Bluegill
Phillip Goodyear and David H. Bennett
Immature bluegills, Lepomis macrochirus
[N= 389], were collected from Par Pond, a 1,120 hectare impoundment on the
United States Department of Energy’s Savannah river Plant near Aiken, South
Carolina, and tested individually by observing their directional movement from
the center of a circular testing facility.
Bluegills captured 10-20m from shore in areas lacking extensive submerged
vegetation swam in a direction which would have taken them to shore at the area
of their capture, whereas those taken from areas having submerged vegetation
offshore swam in the direction opposite from shore. The directional responses of fish that were phase shifted by
6 hours demonstrated that they were using time-compensated sun orientation.
Fish exposed to a predator oriented in the direction of shore in their
training facility, but if no predators had been present during training, moved
in the direction of deep water. Present
evidence indicates that immature bluegills use their sun compass mechanism in
oriented movements and that he observed behavior is probably related to
avoidance of their predators.
SREL Reprint #0637
Goodyear, C.P. and D.H. Bennett. 1979. Sun compass
orientation of immature bluegill. Transactions of the American
Fisheries Society 108:555-559.