Zoo Outreach Organization &
Wildlife Information Liaison Development


 ZOO/WILD's 2013-2016 Activities . . .

Evaluation of the Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis) on the amphibians of the Western Ghats.

First of all… Why is this study essential?
The Western Ghats, is a stretch of forests parallel to the west Coast of India. It is among the 34 biodiversity hotspots of the world owing of its high diversity of endemic species, most of which are under threat because of several human influenced factors. The Western Ghats is rich in amphibian diversity with 182 known species of which 160 species (88%) are endemic to this region. This zoogeographical area hosts five freshwater eco regions encompassing thousands of streams and other water bodies. As per the IUCN red list of threatened species more than 43% of amphibians are threatened with extinction. They are either Critically endangered (CR), Endangered (EN) or Vulnerable (VU) due to anthropogenic factors such as habitat destruction and confined populations.

Information on diseases which pose as a threat to amphibian populations is inadequate. Chytridiomycosis is a dreaded fungal disease of amphibians, which threatens more than 200 species of amphibians across the globe, with extinction. There is a single report of the disease from Western Ghats, published in 2011.

So, this project aims to fill in the information gaps on the extent of occurrence of the disease, infection of the disease and its effects on amphibian populations.

Brushing up basics ….
What are amphibians and why is it important to conserve them?
They are cold-blooded vertebrates which consist of Frogs, Caecilians and Salamanders. Unlike humans they lack an inner temperature regulation system and they maintain their body temperatures by changing their position according to the environment. Water is an essential part of their systems, as it helps in regulating the mineral content of their body systems, so minor changes in mineral compositions of the surrounding environment can result in death. Thus, they act as indicators of ecological health.

What is Chytridiomycosis?
It is a fungal disease caused by the Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis). This fungus grows on the skin of amphibians, and blocks the inner mechanisms helping in water regulation of the amphibian body. As an end result it leads to internal bleeding and a heart attack. It was first reported in 1997 from Panama on the Golden frog (Atelopus zeteki) and is now estimated to threaten more than 200 species of amphibians out of the 6000 known species, with extinction.

How does it spread?
It produces zoospores which are carried by water, making amphibians more susceptible than other organisms.

Are there carriers for this fungus?
Yes, like how mosquitoes are carriers for diseases such as malaria, two species of frogs, the African clawed frog (Xenopus laevis) and the American bull frog (Lithobates catesbianus) are vectors of this fungus.

They have in-built immune responses which fight the fungus and as these frogs are highly exported throughout the world for aquariums, and frog leg trade they act as reservoir hosts to spread the disease.

What can be the origin of this fungus in Western Ghats?
Presently, the answer is unclear, but there is a recent increase in the import of the African Clawed Frog (Xenopus laevis) in the last two years via the aquarium trade and reports indicate the release of these frogs by careless hobbyists into the wild leading to the spread of this fungus, which could be one of the reasons for the spread of  fungus within the Western Ghats.

What is the role of WILD to study this disease?
We at WILD are conducting surveys across the Western Ghats to collect information on the occurrence of the disease using a non–invasive swabbing technique.

Our main objectives are:

  1. To standardize a non–invasive field sampling protocol with quarantine procedures.
  2. To standardize laboratory processing protocols to check for the presence or absence of the fungus.
  3. Establish long term monitoring protocols.
  4. Formulate a policy document for the Government of India on import of exotic trade within the country.
  5. Generate maps on the incidence of the disease.
On-going work at WILD:
There are various activities which have taken place as a part of the Amphibian-Chytrid Project this year. The DNA extraction and analysis from swab samples collected until 2014 was initiated and DNA has been extracted from a total of 2100 swab samples. Apart from this DNA extraction and analysis was completed from amphibian specimens from WILD museum and manuscripts on the results of this component of the project are currently being prepared. Field surveys to collect specimens for taxonomic studies was conducted at Ranipuram Vested Forest in Kerala and at areas around Mookambika Wildife Sanctuary. Ground work for preparation of an amphibian field guide is presently underway for which information was compiled and diagrams were prepared. Also, for the Amphibian assessment due in 2016, species accounts was compiled. Protocols for conduct of a population monitoring study at an organic coffee plantation at Coorg is currently underway.

I am interested to join in surveys, can I?
Yes, you can. But, you need to understand that this is serious work involving strict quarantine procedures and night surveys. We need people who will be responsible about themselves and can handle basic instruments like a GPS and a pH meter. It will be an added advantage if you are a good photographer.

I have understood to an extent about this infection, is there anyway I can help?
Oh yes, you can.
Don’t buy exotic animals as pets, they mess up ecological balance when released into the wild.
Report any fishy incidence of mass deaths of frogs or toads which you come across. You could write to us at wild@zooreach.org.

Click and share photographs of any infection on amphibians which you come across like a disfigured limb or a piece of skin coming out. And most importantly, don’t forget to pass on the information. For more queries contact us at wild@zooreach.org.