Where salamanders should be very afraid

Three hot spots in North America highly vulnerable if killer Bsal fungus invades


DON’T LET THE FUNGUS GET ME  North America’s extreme diversity of salamanders (lungless Ensatina eschscholtzii from the West Coast shown) could face catastrophic losses if the deadly Bsal fungus invades via the international live-animal trade. 

T. Yap

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A salamander-killing fungus hitchhiking via the international live-animal trade may prove especially disastrous if it invades three regions of North America.  

Biologists haven’t reported the deadly fungus, Batrachochytrium salamandrivorans, or Bsal, loose on the continent yet, say Tiffany Yap of UCLA and her colleagues in the July 31 Science. But North America’s native salamanders might have little resistance to a disease thought to have jumped out of Asia before going on a recent salamander killing spree in Europe (SN: 11/29/14, p. 6). The researchers warn that Bsal, which can eat away skin, might cause particularly deep population declines or extinctions of these amphibians in swaths of the southeastern United States, the West Coast and Mexico (see maps).

Salamander diversity ranks as one of the great underappreciated treasures of North America. Forty-eight percent of the world’s 676 known species scurry around the continent.

The risk of fungus invasion via the international live-animal trade is high, Yap and colleagues say. From 2010 through 2014, all U.S. ports combined received more than 768,000 live salamanders either native to Asia or shipped through an Asian port. The most, about 420,000, arrived in Los Angeles, followed by 272,000 in Tampa, Fla. Until regulations are tightened to cope with containing Bsal, the researchers call for an immediate ban on importing live salamanders.  

SALAMANDER HOT SPOTS Darker orange marks North American regions richer in salamander species. Darker purple marks the sparser zones. Biologists have not recorded the Bsal salamander-killing fungus here yet. But black squares mark the entry-point cities receiving the highest numbers of live animals, many imported as part of the pet trade, which could bring in the plague. T.A. Yap et al/Science 2015
PATHOGEN-FRIENDLY ZONES Biologists don’t know much about where the fungus would prefer to live in the wild. But darker orange shows estimates of the most favorable zones for Bsal; darker purple shows less pathogen-friendly areas. T.A. Yap et al/Science 2015
HIGHLY VULNERABLE Combining estimates of pathogen habitats and records of salamander species richness shows three swaths (dark orange) predicted to be highly vulnerable to a Bsal catastrophe. If the fungus arrives, salamander losses in these zones could be especially great. T.A. Yap et al/Science 2015

Susan Milius is the life sciences writer, covering organismal biology and evolution, and has a special passion for plants, fungi and invertebrates. She studied biology and English literature.

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