Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Captive breeding introduced infectious disease to Mallorcan amphibians

23.09.2008
A potentially deadly fungus that can kill frogs and toads was inadvertently introduced into Mallorca by a captive breeding programme that was reintroducing a rare species of toad into the wild, according to a new study published today in the journal Current Biology.

The study, by researchers from Imperial College London and international colleagues, reveals that captive Mallorcan midwife toads released into the wild in 1991 were infected with the chytrid fungus Batrachochytrium dendrobatidis (Bd). Measures to screen the health of the toads did not pick up the fungus, because at the time it was not known to science.

The chytrid fungus, which lives in the water and on the skin of host amphibians such as frogs, toads, salamanders and newts, has been known to cause amphibian population extinctions in Europe. Globally, the disease has been found in over 87 countries and has driven rapid amphibian declines in areas including Australia and Central America, pushing some species to extinction. Bd is currently rare in the UK, having only been detected in three locations.

The new study suggests that an endangered species of frog from South Africa, Xenopus gilli, which was housed in the same room as the Mallorcan midwife toads, was responsible for spreading the infection to them.

The captive breeding and reintroduction programme for the Mallorcan midwife toad has been highly successful in increasing the numbers of the rare toad on the island. Over half of all the current populations on Mallorca are derived from reintroductions.

Although the chytrid fungus can be deadly, toads appear to be doing well in three out of the four populations in Mallorca infected with the chytrid fungus. This finding suggests that there are unidentified factors that are preventing these populations from extinction. The situation is being closely monitored by the Mallorcan conservation authorities.

Global efforts to save amphibians from extinction hinge on species being taken into captivity and bred until they can be reintroduced to the wild. The researchers behind the new study say their findings reveal the risks of reintroducing species into the wild even when health screening is carried out, and highlight the need to ensure that species bred in captivity do not become infected with pathogens from other species.

As soon as Bd was discovered in the late 1990s, screening for the disease was incorporated into amphibian conservation plans. Zoos are now moving towards breeding threatened frogs in strictly quarantined, biosecure facilities in an effort to prevent the disease spreading in captivity.

The chytrid fungus has also been added to a list of diseases that need to be quarantined compiled by the World Organisation for Animal Health. It is hoped that these quarantine measures will help those involved in conservation efforts to stop Bd from spreading further, by controlling the international trade in infected animals.

Dr Mat Fisher, one of the authors of the study from the Department of Infectious Disease Epidemiology at Imperial College London, said: "Our study has shown that species reintroduction programs can have unpredicted and unintended effects. However in this case we believe that the toads are going to survive the infection. The global conservation community is united in its goal of saving species from the effects of Bd and we now have international legislation which should prevent this disease being accidentally introduced into the wild."

The researchers reached their conclusions after comparing the specific genotype of Bd from infected wild toads from across Mallorca, and infected toads from mainland Spain, the UK and the rest of the world. They found that the disease in all Mallorcan toads was of the same genotype, and that this was a different genotype from those on mainland Europe and elsewhere.

Bd infects amphibians' skin and is thought to interfere with their ability to absorb water. Over 257 amphibian species are known to be affected by Bd. Some species are very susceptible and die quickly while others, which are more resistant, are carriers of the pathogen.

Laura Gallagher | alfa
Further information:
http://www.imperial.ac.uk

More articles from Studies and Analyses:

nachricht Real-time feedback helps save energy and water
08.02.2017 | Otto-Friedrich-Universität Bamberg

nachricht The Great Unknown: Risk-Taking Behavior in Adolescents
19.01.2017 | Max-Planck-Institut für Bildungsforschung

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Biocompatible 3-D tracking system has potential to improve robot-assisted surgery

17.02.2017 | Medical Engineering

Real-time MRI analysis powered by supercomputers

17.02.2017 | Medical Engineering

Antibiotic effective against drug-resistant bacteria in pediatric skin infections

17.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>