In the late 1980’s more than 200 species of amphibians came under tremendous threat from a deadly fungus called Batrachochytrium dendrobatidis (Bd). Many species suffered, but frogs in Australia and Central American rainforests were particularly hard hit with the disease wiping out over 40% of species in some regions. Bd has been described as the greatest disease threat to biodiversity.

Now researchers have discovered a related fungus that migrated from Asia to Europe where it has brought the Fire salamanders (Salamandra salamandra) in the Netherlands to the brink of extinction. The disease caused by Batrachochytrium salamandrivorans (Bs) is lethal to salamanders and newts and highly transmissible. The screening of samaples of more than 5000 individual amphibians from 4 continents have shown that in Europe the disease have thus far spread to the Netherlands and Belgium,  while 4% of salamanders from Thailand, Vietnam and Japan tested positive for Bs.  The samples from the Americas were clean.

The threat posed by the disease is exacerbated by the fact that even though the Asian species showed resistance to the disease, they continue to shed fungal spores for at least five months, which means the disease could also be spread by other animals, including amphibians, or by simply floating downstream. Research have shown that 9 of 10 European salamander species were susceptible to the disease. For North America, considered the hotspot of salamander biodiversity with about 190 species, the spreading of the disease could spell disaster. Testing done on abundant and wide spread species such as the Eastern red-spotted newt (Notophthalmus viridescens) and the Rough-skinned newt (Taricha granulosa) have shown 100% mortality. The disease could potentially devastate hundreds of species.

Between 2001 and 2009 an estimated 2.3 million Chinese fire belly newts (Cynops orientalis) were imported into the United States alone. The threat posed by Bs clearly shows why the global exotic pet trade needs to be regulated more aggressively. Many researchers feel the World Customs Organization should develop a tracking system for the amphibian trade in the same manner they monitor the movements of other goods. Once the fungus is introduced in a region, it may be too late to prevent extinctions.

References

A. Martel, M. Blooi, C. Adriaensen, P. Van Rooij, W. Beukema, M. C. Fisher, R. A. Farrer, B. R. Schmidt, U. Tobler, K. Goka, K. R. Lips, C. Muletz, K. R. Zamudio, J. Bosch, S. Lotters, E. Wombwell, T. W. J. Garner, A. A. Cunningham, A. Spitzen-van der Sluijs, S. Salvidio, R. Ducatelle, K. Nishikawa, T. T. Nguyen, J. E. Kolby, I. Van Bocxlaer, F. Bossuyt, F. Pasmans. Recent introduction of a chytrid fungus endangers Western Palearctic salamanders. Science, 2014; 346 (6209): 630 DOI: 10.1126/science.1258268 

Images

Featured image

Fire salamander (Salamandra salamandra): © M.R. Swadzba | Fotolia

Gallery images

Fire salamander (Salamandra salamandra) By Steffen Häuser („own work”) [Public domain], via Wikimedia Commons

Rough-skinned newt (Taricha granulosa) © Vibe Images | Fotolia

Eastern red-spotted newt (Notophthalmus viridescens)  By Bruce Lucas (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons