Vol. 49 No. 2, 2010
Turning Night into Day: Effects of Stress on the Self-Feeding Behaviour of the Eurasian Perch Perca fluviatilis
Keno Ferter1 and Victor Benno Meyer-Rochow1,2,*
1Faculty of Engineering and Sciences, Jacobs University, Research II, D-28759 Bremen, Germany
2Department of Biology, University of Oulu, SF-90300 Oulu, Finland
Keno Ferter and Victor Benno Meyer-Rochow (2010) Effects of stress on the feeding behaviour of the Eurasian perch Perca fluviatilis
were investigated. Over a period of 32 d, the selffeeding
patterns of a group of 4 fish were monitored with a light-dark cycle of
12:12 h. As the perch could obtain food by triggering a feeding
apparatus at any time, food availability likely did not govern the
feeding activity pattern. During the light phase, when the perch
were exposed to an illumination of 2.4 W/m2, they were
repeatedly (but at irregular times) disturbed through
surface-transmitted vibrations and shadows. Monitoring of the
self-feeding pattern over a 24 h period showed that the fish changed
their feeding activity from diurnal to nocturnal when exposed to this
type of stress in combination with the relatively bright illumination
during daytime hours. In order to show that the perch associated
the trigger with food and pulled it intentionally rather than randomly,
the feeding apparatus was emptied while trigger activation was
monitored for a further 6 d. As soon as food was no longer
available from the feeding apparatus the perch decreased their pulling
activity until they had completely lost interest 6 d later.
Key words: Aquaculture, Demand feeding, Biorhythms, Food procurement, Vision.
*Correspondence: Tel:49-421-2003242. E-mail:b.meyer-rochow@jacobs-university.de
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