Predation by signal crayfish Pacifastacus leniusculus on fish eggs and its consequences for coregonid recruitment |
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| Authors: | J. Karjalainen T. J. Ruokonen T. J. MarjomäKi A. Martikainen M. Pursiainen J. Sarvala M. Tarvainen A.‐M. Ventelä |
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| Affiliation: | 1. Department of Biological and Environmental Science, P. O. Box 35, University of Jyv?skyl?, 40014 Jyv?skyl?, Finland;2. Finnish Game and Fisheries Institute, Survontie 9/Technopolis, 40500 Jyv?skyl?, Finland;3. Department of Biology, University of Turku, FI‐20014 Turku, Finland;4. Pyh?j?rvi Institute, Sep?ntie 7, 27500 Kauttua, Finland |
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| Abstract: | The character and magnitude of predation by the invasive, ectothermic Pacifastacus leniusculus, a crayfish widely introduced to Europe and Japan from North America, on the eggs of coregonid fishes, vendace Coregonus albula and whitefish Coregonus lavaretus were examined by experimentation, modelling and field data. The present results showed that P. leniusculus has the potential to be very efficient predator of fish eggs under winter conditions, but the predation by P. leniusculus did not significantly decrease production of coregonid larvae during the years with a high P. leniusculus population in the study lake. Hence, the mortality caused by the novel invertebrate predator appeared to compensate for other yet unexplored mortality factors instead of having an additive effect on the present salmonids. |
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| Keywords: | bioenergetics egg mortality stable‐isotope analysis vendace whitefish winter temperatures |
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