Freshwater turtle (Mauremys rivulata) crosses the Aegean Sea-Turtle Found in Eastern Mediterranean, from southeast Europe and Greece to western Turkey and as far as Lebanon, Israel, Syria and the islands of Crete and Cyprus. – via Herp Digest

 Date: April 7, 2014

Source: Senckenberg Research Institute and Natural History Museum

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 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.

Story Source:

The above post is reprinted from materials provided by Senckenberg Research Institute and Natural History Museum. Note: Materials may be edited for content and length.

Journal Reference:

Melita Vamberger, Heiko Stuckas, Dinçer Ayaz, Petros Lymberakis, Pavel Široký, Uwe Fritz. Massive transoceanic gene flow in a freshwater turtle (Testudines: Geoemydidae:Mauremys rivulata). Zoologica Scripta, 2014; DOI: 10.1111/zsc.12055

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Senckenberg Research Institute and Natural History Museum. "Freshwater turtle crosses the Aegean Sea." ScienceDaily. ScienceDaily, 7 April 2014. <www.sciencedaily.com/releases/2014/04/140407090611.htm>.

Massive transoceanic gene flow in a freshwater turtle (Testudines: Geoemydidae: Mauremys rivulata) – via Herp Digest

Zoologica Scripta /Article first published online: 3 APR 201

1. Melita Vamberger¹,
2. Heiko Stuckas¹,
3. Dinçer Ayaz²,
4. Petros Lymberakis³,
5. Pavel Široký⁴ and
6. Uwe Fritz^1,*

Author Information

1. ¹Museum of Zoology (Museum für Tierkunde), Senckenberg Dresden, Dresden, Germany
2. ²Faculty of Science, Biology Department, Zoology Section, Ege University, Bornova, Izmir, Turkey
3. ³Natural History Museum of Crete, University of Crete, Irakleio, Crete, Greece
4. ⁴Department of Biology and Wildlife Diseases, Faculty of Veterinary Hygiene and Ecology, University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic

Email: Melita Vamberger (melita.vamberger@senckenberg.de), Heiko Stuckas (heiko.stuckas@senckenberg.de), Dinçer Ayaz (dincer.ayaz@ege.edu.tr), Petros Lymberakis (lyberis@nhmc.uoc.gr), Pavel Široký (sirokyp@vfu.cz), Uwe Fritz (uwe.fritz@senckenberg.de)

^*Corresponding author: Uwe Fritz, Museum of Zoology (Museum für Tierkunde), Senckenberg Dresden, A. B. Meyer Building, 01109 Dresden, Germany. E-mail: uwe.fritz@senckenberg.de

The freshwater turtle Mauremys rivulata ranges from the Adriatic coast of the Balkan Peninsula through the Aegean region and coastal western and southern Turkey southwards to Israel. In addition, it occurs on several Aegean islands, Crete and Cyprus. Previous investigations using mtDNA sequences found virtually no genetic differentiation across its distribution range, despite some major biogeographical barriers for terrestrial and freshwater biota. Thus, the absence of any phylogeographical differentiation would be unexpected. To re-examine genetic differentiation within M. rivulata, here we use a comprehensive rangewide sampling and information of 13 unlinked polymorphic microsatellite loci and compare these data against mtDNA variation. Our microsatellite analyses reveal a weak population structuring which conflicts, however, with most biogeographical barriers. We conclude that the genetic structure in the vast majority of the species' range has been shaped by massive transoceanic gene flow. This explanation is unlikely for the northernmost populations, which seem rather to be genetically impacted by intentionally released foreign turtles.

Recent seizures highlight trouble for Asia’s tortoises and freshwater turtles - via Herp Digest

Thursday, March 27, 2014 at 10:38

TRAFFIC in Herpetological, In Asia

Indian Narrow-headed Softshell Turtles seized during at attempt to smuggle them via Bangkok © TRAFFIC Bangkok, Thailand, 27th March 2014—Hot on the heels of three major tortoise and freshwater turtle seizures in Asia comes another in Bangkok involving close to 300 animals and the arrest of two men suspected of smuggling them.

On 12th March, Royal Thai Customs officers discovered 218 Black Spotted Turtles Geoclemys hamiltonii and 54 Indian Narrow-headed Softshell Turtles Chitra indica in check-in luggage.

The two Indian nationals, who took a flight from Gaya and Varanasi in India to Bangkok, were due to board a flight to Macau when their luggage was checked and the animals found.

Initial investigations show the end destination for the turtles was Hong Kong. The duo has been handed over to Royal Thai Police for further investigations.

“This previously unknown trade route for smuggling turtles from Gaya and Varanasi to Bangkok is often used by religious tourists,” said Dr Shekhar Kumar Niraj, Head of TRAFFIC in India.

The involvement of Thailand, India and Hong Kong in the illegal trade in rare tortoises and freshwater turtles was highlighted earlier this year when over a thousand specimens were confiscated from smugglers in three separate seizures. All three seizures passed through Bangkok, with at least two involving tortoises and freshwater turtles originating from India.

One of these recent seizures, which took place on 31st January, also included a number of Black Spotted Turtles, a species listed in Appendix I of CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora), which therefore cannot be traded internationally for commercial purposes.

Another case involved a further 65 Black Spotted Turtles, discovered by Thai Customs and wildlife checkpoint officers at Don Mueang International Airport in unclaimed bags on board a flight from Chennai, India, along with 440 Indian Star Tortoises Geochelone elegans.

Both the Endangered Indian Narrow-Headed Softshell Turtle and the Indian Star Tortoises are listed in Appendix II of CITES, meaning any shipments must be accompanied by appropriate permits. Both species occur in South Asia and are known to be traded for meat and as exotic pets.

India is not the only player in the trade from South Asia in tortoises and freshwater turtles. Seizures of cargoes in Bangkok originating in Bangladesh and Pakistan have also been recorded in the past 12 months.

There are also trade dynamics that point to intra-regional movements of these species. In February 2014, 5000 softshell turtles were seized in West Bengal en route to Bangladesh.

“Co-operation between India and other member countries of the South Asia Wildlife Enforcement Network (SAWEN) is essential to combat the increasingly organised nature of wildlife crime in the region, and connect to destinations in Thailand, Hong Kong and other parts of Asia,” said TRAFFIC’s Dr Niraj.

TRAFFIC’s experience across Asia is being marshalled to support governments – through information exchange, international dialogues, species identification skills, and other capacity building efforts – to take the fight against illegal trade a notch higher.

“Catching the mules of the trade won’t be enough to stop the organized criminal elements that are driving the regions rare tortoises and freshwater turtles to the brink,” said Dr Chris R. Shepherd, Regional Director for TRAFFIC in South-East Asia.

“Seeking out and stopping the big guns that control this trade should be the real focus of enforcement action.”

Freshwater turtle crosses the Aegean Sea

Date:

April 7, 2014

Source:

Senckenberg Research Institute and Natural History Museum

Summary:

Scientists 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 kilometers of sea.

Continued

Climate Change Threatens Endangered Freshwater Turtle in Australia-The Mary River Turtle - via Herp Digest

July 2, 2011 — The Mary river turtle (Elusor macrurus), which is restricted to only one river system in Australia, will suffer from multiple problems if temperatures predicted under climate change are reached, researchers from the University of Queensland have shown.

The scientists, who are presenting their work at the Society for Experimental Biology Annual conference in Glasgow on 3rd July 2011, incubated turtle eggs at 26, 29 and 32⁰C. Young turtles which developed under the highest temperature showed reduced swimming ability and a preference for shallower waters.

This combination of physiological and behavioural effects can have dual consequences for survival chances. "Deeper water not only provides the young turtles with protection from predators but is also where their food supply is found," explains PhD researcher, Mariana Micheli-Campbell. "Young turtles with poor swimming abilities which linger near the surface are unable to feed and are very likely to get picked off by birds. These results are worrying as climate change predictions for the area suggest that nest temperatures of 32⁰C are likely to be reached in the coming decades."

The Mary river turtle is already listed as endangered by the IUCN Red List and the population has suffered a large decline over the past decades. Some factors known to have affected the population include collection of the eggs for the pet trade and introduced predators such as foxes and dogs. "Whether climate change has already contributed to the decline is not clear," says Ms. Micheli-Campbell. "But these results show it may be a danger to this species in the future."

These findings may be shared by other species of turtle, but the outcome is likely to be more extreme in the Mary River turtle as climatic warming is particularly pronounced for this area and the relatively shallow nests of freshwater turtles are more susceptible to changes in ambient temperature than the deeper nests of sea turtles. Further research is needed to understand the effects of climate change on incubation in other turtles.

Story Source:

The above story is reprinted from materials provided by Society for Experimental Biology.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.