Haematoloechus Lung Flukes in American Bullfrogs: Prevalence and Associations of Infection

Abstract

2019 AcknowledgementsEndless thanks go to my advisor, Dr. Susan Masta, for continuously sparking my curiosity, not only in regard to this work, but about all of the little things that run the world. The thoughtful instruction and counsel she has provided has thoroughly changed me and my outlook.Additional gratitude goes to Dr. Kyle Tidwell, whose own intensive work, collecting and studying these frogs, made my own research possible. Thank you to Dr. Trevor Scheffles and all the Conboy Lake National Wildlife Refuge employees for providing lodging, specimen collection permits, and specimen storage. Dr. Debbie Duffield contributed not only a space in her lab, but also continual encouragement and support for this work. Thanks to Lacey Novak for her dedicated time in the lab and for providing me with delightful and sincere conversation. For dissecting with me and asking the foundational questions about flukes, I am grateful to Arani Cuevas-Sanchez. Finally, I would like to acknowledge Konrad Miziolek, whose faith in me and willingness to confer over all manner of things has been invaluable. AbstractThe prevalence and intensity of infection by lung flukes (Haematoloechus sp.) was examined by dissecting 1,590 American bullfrogs (Rana catesbeiana) collected between 2013 and 2018, from Conboy Lake National Wildlife Refuge, Washington. Overall infection, across all age classes, was 59.7% (n=1,580) and mean intensity was 17 (n=169; SD=19.3, range=1-166). A logistic regression model showed a significant relationship between infection and frog snout-to-vent length, gape, and collection year. Sex had a significant relationship to infection (χ 2 =7.31, df=1, P=0.007). Presence of odonates in the stomach was also significantly related to infection (χ 2 =22.49, df=1, P<0.001). This study expands on the current breadth of knowledge on this taxon in anurans into a previously unstudied region of the United States and emphasizes the use of odonates as secondary intermediate hosts.