Gregory Ruthig

Professor of Biology


+1 630 637 5186

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Emerging infectious diseases are responsible for mass amphibian declines and extinctions around the world. I focus on several emerging pathogens of amphibians, including ranaviruses, water molds, and the amphibian chytrid fungus. I study these pathogens on multiple scales, ranging from field surveys to laboratory experiments and molecular genetics. This research approach allow undergraduates with diverse interests to work on a system that encompasses the fields of zoology, ecology, medicine, disease biology, genetics, and conservation biology. 

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Selected Scholarship

Ahmed, A. K., V.C. Sijercic, R. Sayad, G.R. Ruthig, S.F. Abdelwahab, M.A. El-Mokhtar, and I.M. Sayed, I. M. 2023. Risks and preventions for pregnant women and their preterm infants in a world with COVID-19: A narrative review. Vaccines 11(3): 640.


Ruthig, G.R., L.J. Bode, A. Cvetkovic, and P. Shrestha. 2020. Dead mink frogs (Lithobates septentionalis) found in Northern Minnesota were infected with both Batrachochytrium dendrobatidis and Ranavirus. Herpetological Review 51:744-746.


Ruthig, G. R. and A. E. Gramera. 2019. Aggregations of olive ridley sea turtle (Lepidochelys olivacea Eschscholtz, 1829) nests leads to increased human predation during an arribada event. Herpetology Notes 12: 1-7.


Ruthig, G. R. 2013. Temperature affects disease susceptibility of frog eggs to infection by water molds. Herpetological Biology and Conservation 8: 707-714


*Ruthig, G. R. and K. N. Provost-Javier. 2012. Multihost saprobes are facultative pathogens of the bullfrog, Lithobates catesbeianus eggs. Diseases of Aquatic Organisms 101: 13-21. 


Ruthig, G. R. and B. P. DeRidder. 2012. Fast quantitative PCR, locked nucleic acid probes, and reduced volume reactions are effective tools for detecting Batrachochytrium dendrobatidis DNA. Diseases of Aquatic Organisms 97: 249-253.


Davidson, E. D., J. Snyder, D. Lightner, G. R. Ruthig, and J. Gilley. 2010. Exploration of potential microbial control agents for the invasive crayfish, Orconectes virilis, in Arizona, USA.  Biocontrol Science & Technology 20: 297-310. 


Schock, D. M., G. R. Ruthig, J. P. Collins, S. J. Kutz, S. Carrière, R. J. Gau, A. Veitch, N. C. Larter, D. P. Tate, G. Guthrie, D. G. Allaire, and R. Popko. 2009. Amphibian chytrid fungus and ranaviruses in the Northwest Territories, Canada.  Diseases of Aquatic Organisms. doi: 10.3354/dao02134


Ruthig, G. R. 2009. Water molds of the genera Saprolegnia and Leptolegnia are pathogenic to the North American frogs, Rana catesbeiana and Pseudacris crucifer, respectively. Diseases of Aquatic Organisms 84: 173-178.


Karraker, N. E. and G. R. Ruthig. 2009. The interaction between road salt and water molds on amphibian egg mortality. Environmental Research 109: 40-45.         


Ruthig, G. R. 2008. The influence of temperature and spatial distribution on the susceptibility of southern leopard frog eggs to disease. Oecologia 156: 895-903.


*Pasachnik, S. and G. R. Ruthig. 2004. Versatility of habitat use in three sympatric species of Plethodontid salamanders. Journal of Herpetology 38: 434-437.


* Denotes a publication that was co-authored with an undergraduate researcher



Courses Taught

Biological Investigations


Field Biology

Animal Biology

Infectious Disease


Environmental Science