Destructive Snake Disease Discovered in Museum Specimens

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A recent study of museum snake specimens shows that snake fungal disease, a skin infection threatening many important snake populations, existed in the U.S. over 50 years earlier than previously thought. 

Rat snake museum specimen

This rat snake is a preserved museum specimen with snake fungal disease that was collected in Tennessee in 1973. (Credit: Jeff Lorch, USGS)

Wild snakes are critical to ecosystem health and biodiversity, but snake fungal disease puts some snake populations at risk. Scientists with the U.S. Geological Survey and University of Kentucky examined 524 snake specimens in two museum collections to determine how long snake fungal disease has been in North America. They found evidence of snake fungal disease in specimens dating back to 1945, about 55 years before the disease was first reported in the U.S.  

“Our discovery that snake fungal disease was present but undetected for so long suggests that other factors like climate change and environmental conditions may be driving recent outbreaks,” said Jeff Lorch, a USGS scientist and the study’s lead author. “Pinpointing the factors that cause outbreaks can inform management decisions to better protect snake populations.” 

Scientists first documented snake fungal disease in wild snakes in North America in 2008. The disease has since been found throughout the eastern U.S. and was detected in Europe. Caused by the fungus Ophidiomyces ophidiicola, snake fungal disease can lead to skin lesions, scabs and crusty scales, which can be deadly for some snakes. Affected species include threatened snakes such as the eastern massasauga rattlesnakeeastern indigo snake and Louisiana pinesnake.  

“Natural history museum collections can provide valuable historical samples that could not otherwise be obtained,” said Laura Monahan, Curator of Collections at the University of Wisconsin-Madison Zoological Museum. “Dr. Lorch’s work highlights the modern research that can be done with very old museum specimens.”  

The researchers examined preserved snake specimens from the University of Wisconsin Zoological Museum and Morehead State University Museum Collection. They found visual signs of snake fungal disease in 47, or 9%, of the specimens. The scientists further analyzed 12 of those 47 specimens and found microscopic evidence of skin damage in seven samples and DNA from the O. ophidiicola fungus in three samples. 

“Our study highlights the importance of examining preserved specimens in museum collections to trace the origin of fungal pathogens like Ophidiomyces ophidiicola,” said Steven Price, an associate professor in the Department of Forestry and Natural Resources at the University of Kentucky College of Agriculture, Food and Environment. 

The study is published in the journal Emerging Infectious Diseases. For more information about USGS wildlife disease research, please visit the USGS National Wildlife Health Center website

Examples of Snake Fungal Disease (SFD)

These images are examples of snake fungal disease on a broad-banded watersnake. (Credit: USGS)