Tagging, displacement and recapture, and ultrasonic tracking of displaced mature Sunapee trout (Salvelinus alpinus) in Floods Pond, Maine, demonstrated that rapid within-season homing occurs in this relict form of Arctic char. Of the trout displaced about 1.8 km from their spawning ground from 1972 to 1975, 9% to 32% were recaptured one to four times within the same spawning season in trap nets set on the spawning ground. Eight of 14 trout tracked ultrasonically in 1975 horned in 2.5 to 10.0 h. Movements of the homing fish were variable; some trout homed paralleling the shoreline, others horned in open water or used a combination of near-shore and open-water movements. Behavior was similar between the sexes and during day and night, although two fish did begin to move just at sundown. Swimming speeds ranged from 15 to 35 cm s-1and averaged about 0.6 body lengths s-1. Swimming directions were not influenced by wind and wave direction, nor were swimming speeds within individual tracks influenced by cloud cover, wave height, or water depth. Heavy overcast at night may have inhibited movement.
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