The eye fluke Tylodelphys clavata affects prey detection and intraspecific competition of European perch (Perca fluviatilis)
Parasites that occupy the eyes of fish have the potential to affect visual perception and consequently alter the host’s behaviour, as these organs provide information about their surroundings. In an experimental study, the feeding behaviour of European perch (Perca fluviatilis) infested with the eye fluke Tylodelphys clavata was examined. The results showed that an individual’s ability to identify and approach food items was negatively affected by the infestation intensity of T. clavata. Additionally, the foraging success of an individual was reduced in competition with another, less heavily infested conspecific, when the same food resource was exploited. These alterations in the ability to locate food may have important consequences on the feeding strategy of the fish. Furthermore, the impaired feeding capability caused by T. clavata may also increase the predation risk as heavily infested fish need to spend more time foraging to attain a rate of food intake equivalent to less infested conspecifics.
KeywordsTylodelphys clavata Eye fluke Perca fluviatilis Fish-parasite interaction Foraging Competition
We are grateful to Karena Kuntze for her technical and logistic assistance. Further, we would like to thank Mathias Kunow for his support in catching the fish. This research was supported by the Graduate School IMPact-Vector funded by the Senate Competition Committee grant (SAW-2014-SGN-3) of the Leibniz-Association.
Compliance with ethical standards
The experiments were conducted in accordance with the German Animal Welfare Act and were approved by the Berlin State Office for Health and Social Affairs (LaGeSo, reference number G 0215/13).
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