Keynote-Vorträge
Auch in diesem Jahr wird es wieder einleitende Keynote-Vorträge von eingeladenen Kollegen und Kolleginnen zu ausgewählten Themen geben.
- Lukas Rüber, Naturhistorisches Museum Bern
Diversity and evolution of Cypriniforms: tiny fishes in extreme habitats
Abstract: Cypriniformes is the most species-rich order of freshwater fishes, comprising more than 5,000 described species, with many more yet to be discovered. Members of this order display exceptional morphological, physiological, and ecological diversity and are distributed across Asia, Europe, Africa, and North America. They inhabit an extraordinary range of freshwater environments and span a wide range of body sizes, from miniature species measuring less than 8 mm to freshwater giants exceeding 3 m in length. Several cypriniform species are important model organisms in various research fields, and many species are economically and culturally significant, playing a vital role in aquaculture and the ornamental fish trade. Despite their importance, many aspects of the evolutionary history of Cypriniformes remain unresolved. Previous phylogenetic studies have been limited by sparse taxon sampling and restricted genetic data, resulting in persistent uncertainty and conflicting relationships. I will introduce the first phylogenomic analysis of Cypriniformes, based on a complete family-level sampling and broad genus-level coverage to examine the evolution of miniaturisation — the extreme reduction in adult body size — within this fascinating fish group.
Forschung/Research: My main research interest is in line with one of the central themes in evolutionary biology, namely understanding the processes that contribute to the origin and maintenance of biodiversity. The diversity of recent species is not equally distributed among taxonomic groups and across the globe – a small number of clades accounts for a large part of the world’s diversity and a number of relatively small areas with high levels of endemism are populated by unusually large numbers of species. I study patterns and processes of diversification at different spatial and temporal scales by focusing on fish adaptive radiations and biodiversity hotspots.
- Jacco van Rijssel, Wageningen University
Migratory fish species recovery
Abstract: Migratory fish species show a global decline, and the populations in the Rhine and Meuse river systems are no exception to that. In this talk, we will lay out these declines and try to find out what the current causes are for the lack of recovery of these populations. The results of several very recent studies will be presented. We will start off with the diet and behavior of European catfish around a large migration barrier in the Meuse river, followed by the effects of commercial fisheries on migratory fish species at the Haringvliet sluices; the main entrance used by migratory fish to enter the rivers Rhine and Meuse. The bycatch of migratory fish will be put in perspective by showing the results of (natural) predation on Atlantic salmon smolts, Sea trout and North Sea Houting around the Haringvliet sluices, which were fitted with acoustic predation tags. At the end, implications of these results for migratory fish species recovery will be discussed.
Forschung/Research: I am an evolutionary ecologist at heart and my current focus is mainly on freshwater fish and migratory fish species. I try to make sense of yearly fish monitoring trends conducted in the Rhine and Meuse river systems including the larger Dutch freshwater lakes. More recently I got involved in tracking migratory fish species to learn more about their behavior to eventually use this information to restore their population sizes.
- Kristin Scharnweber, Universität zu Köln, Ökologische Forschungsstation Rees
Trophic interaction within and among ecosystems
No species exists in a vacuum. Instead, species are embedded within complex networks of predator–prey interactions, commonly referred to as food webs. In freshwater ecosystems, fish often occupy higher trophic levels and can strongly influence food-web structure, with cascading effects on nutrient cycling and energy flow. The introduction of fish into previously fish-free gravel pit lakes, for example, may alter ecosystem processes such as the establishment of macrophytes. In addition, freshwater food webs can be highly complex and frequently extend beyond aquatic boundaries, incorporating interactions with terrestrial ecosystems. This presentation highlights results from recent studies on the structuring and restructuring forces operating within and among ecosystems.
- Albert Ros, Fischereiforschungsstelle Langenargen, Landwirtschaftliches Zentrum Baden-Württemberg
Durch den Klimastress, neue Krankheitserreger oder invasive Arten verschlechtern sich die Lebensbedingungen für die Fischfauna in Baden-Württemberg rasant. Das Ziel meiner Forschung ist es, konkrete Strategien zu entwickeln, die den Fischen dabei helfen, auf drei Wegen mit der Krise umzugehen: durch das Ausweichen in kühlere Gebiete (move), die biologische Anpassung (adapt) oder das Überleben akuter Hitzeperioden in lokalen Rückzugsorten (persist).“
