Chytrid fungus


Nos complace anunciar que, a partir de la próxima edición del boletín AArk, estaremos ofreciendo nuestro boletín de noticias tanto en inglés como en español.

Si desea suscribirse a la versión en español del boletín, por favor haga clic en el botón de abajo e inscríbase al boletín de español.

Estamos seguros de que nuestros lectores españoles apreciarán esta nueva iniciativa. Nos gustaría transmitir un agradecimiento enorme para Silvia Flores, quien ha ofrecido generosamente a traducir los boletínes para nosotros cada trimestre.

Some interesting news from researchers working in Panama.

Dr. Karen Lips and her team documented the association of disease and the massive decline of amphibians within a protected national park in El Cope, Panama in 2006 (Lips, K. R., Brem, F., Brenes, R., Reeve, J. D., Alford, R. A., Voyles, J., Carey, C., Livo, L., Pessier, A. P. & Collins, J. P. 2006. Emerging infectious disease and the loss of biodiversity in a Neotropical amphibian community. Proc. Nat. Acad. Sci. 103:3165-3170.). Further findings just published by Andrew Crawford, Karen Lips and Eldredge Berminhama in PNAS have shown through DNA barcoding techniques that although 30 species are known to have disappeared from this study site, nearly a dozen more may have disappeared before they were even described to science!

I ran across this recent press on the subject following the publication of their paper and thought I’d share it. http://www.physorg.com/news198764525.html

More information on this publication can be found here: http://www.pnas.org/content/early/2010/07/09/0914115107

Knowing that habitat loss is the number one threat to amphibians and thinking about how many species we KNOW are lost to habitat loss, it makes me think about how these new data may indicate that even more species lost via destruction of their homes is even higher than we know! Not only are species going missing faster than we discover new ones, the rate is much higher than I would have thought.

The Kihansi spray toad used to live in the spray region of the Kihansi waterfall, in Tanzania, and relied heavily on the spray from the waterfall to maintain a constant temperature and humidity in its environment. But due to the construction of a dam which funded by the World Bank, the waterfall has been disrupted, and the Kihansi spray toad has recently been declared Extinct in the Wild.

A number of small populations of this species exist in US zoos, and in spit of several setbacks with the initial population of 500 animals that were collected, the current population now sits at around 470 animals.

How many more species will become extinct in the wild, relying entirely on ex situ “ark” populations for their survival, before we start to take better care of our planet and ALL of its inhabitants?

More information on the Kihansi spray toad can be found here.

Scientists have unravelled the mechanism by which the fungal disease chytridiomycosis kills its victims.

The BBC reports that a group of scientists has published an article in the journal Science that chytrid fungus kills by changing the electrolyte balance of animals, resulting in cardiac arrest. Chytrid, which was discovered in 1998, is one of the major killers of amphibians across the globe, along with habitat destruction and climate change. Curing amphibians in captivity can now be done using antifungal chemicals, but there is currently no way of treating the disease in wild populations.

If scientists can now discover more about how the elctrolyte balance is disrupted, they may also ultimately, discover a way to reduce the mortality rate in wild amphibian populations.

Korean scientists have recently discovered chytrid fungus in introduced bullfrogs in South Korea, although so far, this does not appear to be having an impact on South Korean amphibians. There are thirteen frog and five salamander species in the country, which boats 65 percent of natural forest cover.

Pierre Fidenci, President of Endangered Species International (ESI), talks about the state of amphibians in South Korea in an interview with Mongabay.com, and there is an additional report on The Korean Times web site. In his interview on mongabay.com, Pierre also says:

We put our focus depending on the degree of urgency (not all endangered species have the same degree of extinction, some are much more threatened), our experience and expertise, and the location (we tend to go to places where no other conservation NGOs work). We focus on endangered species found in various types of habitat and serving as protecting umbrella to other endangered species and various wild habitat.

In a similar vein, Amphibian Ark staff have been using an “amphibian species prioritization” process, which is now known as a conservation action planning process  to work with amphibian experts around the world to document their collective knowledge, to produce ordered lists of conservation action required to help save threatened species.

It’s well chronicled that Panama’s amphibians are dying off because of chytrid (background on chytri click HERE). But there are steps that humans can take to slow the spread of chytrid as scientists search for a cure. Here’s a great article from Julie Ray of Examiner.com. In a nutshell, her advice is to take special steps to make sure your boots and wheels don’t accidentally spread chytrid after you visit an infected location.

Six years ago, promises were made by governments from around the world involving the mass extinctions facing so many animal classes, chief among them the amphibian class. The governments vowed to halt the decline in biodiversity by 2o1o. Well, the International Union for Conservation of Nature (IUCN) just issued a report that says, in essence, “let’s not kid ourselves, when next year comes around, it’s going to be bleak.”

IUCN, which puts out the Red List of most endangered species, has produced a 150-page report that details the loss of biodiversity earth has experienced over the last 5 years. “Biodiversity continues to decline and next year no one will dispute that,” said the report’s senior editor. “It’s happening everywhere.”

Here’s a link to story I just read about this.  (Click HERE.)

An excerpt from the IUCN Web site:

The report shows nearly one third of amphibians, more than one in eight birds and nearly a quarter of mammals are threatened with extinction. For some plant groups, such as conifers and cycads, the situation is even more serious, with 28 percent and 52 percent threatened respectively. For all these groups, habitat destruction, through agriculture, logging and development, is the main threat and occurs worldwide.

In the case of amphibians, the fungal disease chytridiomycosis is seriously affecting an increasing number of species, complicating conservation efforts. For birds, the highest number of threatened species is found in Brazil and Indonesia, but the highest proportion of threatened or extinct birds is found on oceanic islands. Invasive species and hunting are the main threats. For mammals, unsustainable hunting is the greatest threat after habitat loss. This is having a major impact in Asia, where deforestation is also occurring at a very rapid rate.

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