Still today, little is known on how this remarkable diversity arose. Scientists of the Biodiversity and Climate Research Centre (BiK-F), the Naturalis Biodiversity Center in Leiden and the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) in Berlin therefore investigated the potential of aquatic insects for research on diversification. The results have now been published in the renowned Annual Review for Entomology.
A typical karst spring and stream in the western Balkan Peninsula that is home to a microendemic caddisfly species of the genus Drusus.
© Ana Previsic
Freshwaters cover less than 1% of the Earth’s surface, but harbour 10% of all animal. Six out of ten of currently known species are insects. In a recently published review an international team of researchers from the Biodiversity and Climate Research Centre (BiK-F), the Biodiversity Center in Leiden, and the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) in Berlin analyzed how studying the vast diversity of aquatic insects may contribute to a better understanding of diversification processes.
„Analyzing the reasons behind the disproportionately high degree of aquatic insect diversity relative to the little area covered by freshwaters may help us to better understand species diversification“, specifies Dr. Steffen Pauls, leader of a junior research group at the BiK-F and one of the authors of the review. All aquatic insect groups are the result of the invasion of freshwaters by terrestrial groups: „Although belonging to only 12 orders, aquatic insects may represent more than 50 separate invasions“, explains co-author Dr. Klaas-Douwe Dijkstra from the Naturalis Biodiversity Center Leiden.
The ecology and habitat preferences of many aquatic insect groups have been intensively studied, due to their roles as disease vectors or bioindicators for water quality. But as this research is mostly done in a purely ecological context, these species are underrepresented in evolutionary studies. „And even inside the entomological community, there is often a lack of communication between experts on different groups of insects. So we hope this review will stimulate more exchange and promote interdisciplinary research “, Dijkstra points out.
He who lives in a safe home, doesn’t need to moveEcological diversity results from a complex set of environmental influences. One important factor affecting diversification is habitat stability. The researchers present a model that explores the correlation of habitat stability, speciation and spreading rates under environmental change of aquatic insects. These processes strongly affect and are intricately linked with the life cycles of aquatic insects, as one and the same species may switch between a non-flying, aquatic immature life stage, and a flying terrestrial adult stage.
Co-author Dr. Michael T. Monaghan, Leibniz-Institute of Freshwater Ecology and Inland Fisheries in Berlin, sums up: „Our model demonstrates a non-linear relationship between habitat stability and dispersal ability of species. Standing waters harbor a larger proportion of species that appear to have evolved the propensity to move to another habitat if conditions change. This can result in the emergence of new species based on geographical diversification. Organisms in running water disperse less, therefore must adapt to changing environmental conditions, which may be another important speciation mechanism. It makes the mixture of habitats an ideal place to study ecological diversification.”
Overview of the research potential of different aquatic insects
The authors summarize and highlight the value of major aquatic insect lineages for biodiversity research.
The diversification of the caddisfly genus Drusus is well suited to investigate speciation taking place at the interface of geographical and ecological diversification. „In the streams and springs of the western Balkan Mountains you can find a whole range of Drusus species. Across the whole mountain range different microendemic species have evolved in every valley– right down to Greece“, says Pauls. „The trigger might be geographical diversification, as waters are isolated by the progressing karst formation“, the entomologist suggests. Different temperature preferences of individual species however, highlight that ecological diversification also plays an important role in the process.Temperature adaptation is another focus of research interest, e.g. in non-biting midges (Chironomidae). These highly adaptive midges with their plumose antennae comprise tropical and antarctic species and occur in altitudes from 6000 above sea level to 1000 below sea level (even in marine environments). They tolerate temperatures from -20° until +40° Celsius, and their lifecycles last from seven days to seven years.
Sabine Wendler | Senckenberg
Fish Oil-Diet Benefits May be Mediated by Gut Microbes
28.08.2015 | University of Gothenburg
Bio-fabrication of Artificial Blood Vessels with Laser Light
28.08.2015 | Fraunhofer-Institut für Lasertechnik ILT
A University of Oklahoma astrophysicist and his Chinese collaborator have found two supermassive black holes in Markarian 231, the nearest quasar to Earth, using observations from NASA's Hubble Space Telescope.
The discovery of two supermassive black holes--one larger one and a second, smaller one--are evidence of a binary black hole and suggests that supermassive...
A team of European researchers have developed a model to simulate the impact of tsunamis generated by earthquakes and applied it to the Eastern Mediterranean. The results show how tsunami waves could hit and inundate coastal areas in southern Italy and Greece. The study is published today (27 August) in Ocean Science, an open access journal of the European Geosciences Union (EGU).
Though not as frequent as in the Pacific and Indian oceans, tsunamis also occur in the Mediterranean, mainly due to earthquakes generated when the African...
In mountainous regions earthquakes often cause strong landslides, which can be exacerbated by heavy rain. However, after an initial increase, the frequency of these mass wasting events, often enormous and dangerous, declines, in fact independently of meteorological events and aftershocks.
These new findings are presented by a German-Franco-Japanese team of geoscientists in the current issue of the journal Geology, under the lead of the GFZ...
Bacteria do not cease to amaze us with their survival strategies. A research team from the University of Basel's Biozentrum has now discovered how bacteria enter a sleep mode using a so-called FIC toxin. In the current issue of “Cell Reports”, the scientists describe the mechanism of action and also explain why their discovery provides new insights into the evolution of pathogens.
For many poisons there are antidotes which neutralize their toxic effect. Toxin-antitoxin systems in bacteria work in a similar manner: As long as a cell...
It comes when called, bringing care utensils with it and recording how they are used: Fraunhofer IPA is developing an intelligent care cart that provides care staff with physical and informational support in their day-to-day work. The scientists at Fraunhofer IPA have now completed a first prototype. In doing so, they are continuing in their efforts to improve working conditions in the care sector and are developing solutions designed to address the challenges of demographic change.
Technical assistance systems can improve the difficult working conditions in residential nursing homes and hospitals by helping the staff in their work and...
20.08.2015 | Event News
20.08.2015 | Event News
19.08.2015 | Event News
28.08.2015 | Physics and Astronomy
28.08.2015 | Health and Medicine
28.08.2015 | Life Sciences