Diel foraging and shelter use of large juvenile brown trout (Salmo trutta) under food satiation
نویسندگان
چکیده
The diel partitioning of juvenile brown trout Salmo trutta foraging behaviour is controlled by a number of factors including predation risk, competition, temperature and food availability. The present study uses PIT-tagging and visual observation to asses the use of shelter and foraging behaviour of Danish wild juvenile brown trout (13.5–15.6 cm). The experiment was conducted in a fluvarium and the fish were fed to satiation. It was hypothesised that food satiation would promote nocturnal foraging and increase daytimeshelteruse.Our resultsshowedasignificantdifference indiel shelter use between day and night with a significant increase in shelter use during daytime conditions. Visual observations showed a significant preference for nocturnal feeding. Togetherwith the significantly reduced shelter useduring the night, our results support the hypothesis that young stream living trout only feed during the day to the extent needed to sustain growth.
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