Ribi
Fakultäten » Mathematisch-naturwissenschaftliche Fakultät » Evolutionsbiologie und Umweltwissenschaften, Institut für » Evolutionary Biology » Prof. Dr. Georg Ribi (verstorben) » Ribi
Completed research project
| Title / Titel | Are native crayfish species of Switzerland endangered? | ||||||
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| Abstract (PDF, 14 KB) | |||||||
| Original title / Originaltitel | Sind die einheimischen Flusskrebse bedroht? | ||||||
| Summary / Zusammenfassung | The aim of the project is to identify the reasons for the decline of native crayfish populations in Switzerland. Possible reasons are water pollution, canalization of streams and interactions with introduced crayfish species including transmission of the crayfish plague Aphanomyces astaci. We investigate the distribution and population structure of natural crayfish populations in Switzerland, and we make laboratory experiments to identify machanisms of competitive displacement between different species. We found that three European crayfish species live in Lake Aegeri. The stone crayfish Austropotamobius torrentium occurs along the northern and eastern shore, whereas the noble crayfish Astacus astacus and the swamp crayfish Astacus leptodactylus live at the southwestern and southeastern part of the lake, respectively (Jann Romer, Diploma thesis 1999). We now want to find out if this distribution is stable or one of the species (most likely A. leptodactylus) is expanding its range at the expense of one or both of the other species. In the canton of Berne, the native crayfish Austropotamobius pallipes has declined during the last ten years. However, there is no indication that A. pallipes is being displaced be the American species Orconectes limosus which lives in Lake Biel and the River Aare. We found no sites with overlapping or neighbouring populations of the two species (Tatjana Mickasch, Diploma thesis 1999). |
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| Publications / Publikationen | Mickasch, T. (1999): Is Orconectes limosus a threat to Austropotamobius pallipes populations in Switzerland? Freshwater crayfish, in press.Stucki, T.P. & Staub, E. (1999): Distribution of crayfish species and legislation concerning crayfish in Switzerland. In: Crayfish in Europe as Alien Species, F.R. Schram (eds). Vol. II of Crustacean Issues, in press.Vorburger, C. & Ribi, G. (1999): Aggression and competition for shelter between a native and an introduced crayfish in Europe. Freshwater Biology, in press. | ||||||
| Keywords / Suchbegriffe | Aphanomyces astaci, Astactus, Austropotamobius, colonization, competition, crayfish plague, crayfish distribution, displacement, Orconectes, Pacifastacus, Procambarus, reproduction | ||||||
| Project leadership and contacts / Projektleitung und Kontakte |
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| Funding source(s) / Unterstützt durch |
Other Public Sources (e.g. Federal or Cantonal Agencies) |
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| In collaboration with / In Zusammenarbeit mit |
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| Duration of Project / Projektdauer | Oct 1996 to Jul 2000 |