title: Predation by signal crayfish Pacifastacus leniusculus on fish eggs and its consequences for coregonid recruitment.
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.
authors.affiliation: Department of Biological and Environmental Science, P. O. Box 35, University of Jyväskylä, 40014 Jyväskylä, Finland.
authors.forename: J
authors.initials: J
authors.lastname: Karjalainen
authors.affiliation: Department of Biological and Environmental Science, P. O. Box 35, University of Jyväskylä, 40014 Jyväskylä, Finland.
authors.forename: T J
authors.initials: TJ
authors.lastname: Ruokonen
authors.affiliation: Department of Biological and Environmental Science, P. O. Box 35, University of Jyväskylä, 40014 Jyväskylä, Finland.
authors.forename: T J
authors.initials: TJ
authors.lastname: MarjomäKi
authors.affiliation: Department of Biological and Environmental Science, P. O. Box 35, University of Jyväskylä, 40014 Jyväskylä, Finland.
authors.forename: A
authors.initials: A
authors.lastname: Martikainen
authors.affiliation: Finnish Game and Fisheries Institute, Survontie 9/Technopolis, 40500 Jyväskylä, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Pursiainen
authors.affiliation: Department of Biology, University of Turku, FI-20014 Turku, Finland.
authors.forename: J
authors.initials: J
authors.lastname: Sarvala
authors.affiliation: Pyhäjärvi Institute, Sepäntie 7, 27500 Kauttua, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Tarvainen
authors.affiliation: Pyhäjärvi Institute, Sepäntie 7, 27500 Kauttua, Finland.
authors.forename: A-M
authors.initials: AM
authors.lastname: Ventelä
keywords: bioenergetics; egg mortality; stable-isotope analysis; vendace; whitefish; winter temperatures