Scientists at the Senckenberg Research Institute in Dresden, together with an international team of researchers, have studied the widely distributed freshwater turtle, Mauremys rivulata. In spite of geographical barriers, the turtles are genetically very similar throughout their vast distribution range. This would indicate that that animals cross hundreds of kilometres of sea. The relevant study is published in the scientific journal “Zoologica Scripta”.
Mauremys rivulata is a turtle, no more than 24 centimetres in size, which is widely distributed in lakes and streams in the region of the Eastern Mediterranean, from southeast Europe and Greece to western Turkey and as far as Lebanon, Israel, Syria and the islands of Crete and Cyprus.
The wide range of the species led the research team of Prof Dr Uwe Fritz, Managing Director at Senckenberg Dresden to study this species of turtle genetically.
“Because of the many geographical barriers in the range of this freshwater turtle – especially the Aegean Sea – we assumed that there would be many genetically different populations. This was based on the consideration that there was no gene flow between the isolated distribution patches, as the sea divides the populations,” says Fritz.
The story that emerged, however, was quite a different one: Using different genetic methods, the scientists examined 340 turtle samples from a total of 63 localities across the entire region of distribution. “The astonishing thing is that even turtles living at great distances from each other display an almost identical genetic pattern, for instance, in southeast Europe and Asian Turkey” explains Fritz. This means that the turtles must have found a means to exchange their genes across large distances – and indeed over hundreds of kilometres of sea.
But how do the animals manage to live on both sides of the Aegean without developing into an individual species over time? “One idea is that the turtles were brought to the different regions by humans, which meant that the gene pool could mix constantly,” explains Melita Vamberger, lead author of the study, and adds: “Yet in contrast to other turtles, Mauremys rivulata was never popular as food, because these animals stink terribly. There is therefore no obvious reason why these turtles should have been transported in such large numbers.”
Thus, only one other – unexpected – possibility remained for the researchers: “We assume that this freshwater turtle is dispersed across the sea. It is likely that turtles are swept repeatedly from their habitats in coastal swamps into the sea by storms. They can obviously survive for a long time in the sea, long enough until they are washed onto some shoreline somewhere. And this occasional exchange is sufficient!”
In fact, some time ago a Mauremys rivulata was caught on open water near Cyprus, which would support this theory.
And whatever a turtle can do might also be a feasible option for others. “It might well be possible,” says Fritz, “that other turtle species take the route across the sea. For instance, this could also explain the weak genetic structure found throughout the widely distributed and endangered North American diamond terrapin (Malaclemys terrapin)”. This could necessitate rethinking conservation measures for this and other species.
Prof. Dr. Uwe Fritz
Tel. +49- 351 - 795841 4326
Tel. +49- 351 795841 4328
Senckenberg Gesellschaft für Naturforschung
Tel. +49- 69 7542 1434
Vamberger, M., Stuckas, H., Ayaz, D., Lymberakis, P., Široký, P. & Fritz, U. (2014). Massive transoceanic gene flow in a freshwater turtle (Testudines: Geoemydidae: Mauremys rivulata). – Zoologica Scripta. DOI: 10.1111/zsc.12055
Judith Jördens | Senckenberg
An evolutionary heads-up – The brain size advantage
22.05.2015 | Veterinärmedizinische Universität Wien
Endocrine disrupting chemicals in baby teethers
21.05.2015 | Goethe-Universität Frankfurt am Main
Physicists have developed an innovative method that could enable the efficient use of nanocomponents in electronic circuits. To achieve this, they have developed a layout in which a nanocomponent is connected to two electrical conductors, which uncouple the electrical signal in a highly efficient manner. The scientists at the Department of Physics and the Swiss Nanoscience Institute at the University of Basel have published their results in the scientific journal “Nature Communications” together with their colleagues from ETH Zurich.
Electronic components are becoming smaller and smaller. Components measuring just a few nanometers – the size of around ten atoms – are already being produced...
Development and implementation of an advanced automobile parking navigation platform for parking services
To fulfill the requirements of the industry, PolyU researchers developed the Advanced Automobile Parking Navigation Platform, which includes smart devices,...
The world's first electrical car and passenger ferry powered by batteries has entered service in Norway. The ferry only uses 150 kWh per route, which...
On Tuesday, 19 May 2015 the research icebreaker Polarstern will leave its home port in Bremerhaven, setting a course for the Arctic. Led by Dr Ilka Peeken from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) a team of 53 researchers from 11 countries will investigate the effects of climate change in the Arctic, from the surface ice floes down to the seafloor.
RV Polarstern will enter the sea-ice zone north of Spitsbergen. Covering two shallow regions on their way to deeper waters, the scientists on board will focus...
Nanoengineers at the University of California, San Diego developed a gel filled with toxin-absorbing nanosponges that could lead to an effective treatment for skin and wound infections caused by MRSA (methicillin-resistant Staphylococcus aureus), an antibiotic-resistant bacteria. This "nanosponge-hydrogel" minimized the growth of skin lesions on mice infected with MRSA - without the use of antibiotics. The researchers recently published their findings online in Advanced Materials.
To make the nanosponge-hydrogel, the team mixed nanosponges, which are nanoparticles that absorb dangerous toxins produced by MRSA, E. coli and other...
20.05.2015 | Event News
18.05.2015 | Event News
12.05.2015 | Event News
22.05.2015 | Materials Sciences
22.05.2015 | Information Technology
22.05.2015 | Materials Sciences