Ribeiroia ondatrae causes limb abnormalities in a Canadian amphibian community

• Published in: Canadian journal of zoology Vol. 90; no. 7; pp. 808 - 814
• Main Authors: ROBERTS, C. D, DICKINSON, T. E
• Format: Journal Article
• Language: English
• Published: Ottawa NRC Research Press 01.07.2012; National Research Council of Canada; Canadian Science Publishing NRC Research Press
• Subjects: abnormalities; Amphibia. Reptilia; Amphibians; Animal populations; anomalies; Biological and medical sciences; Birds; Columbia Spotted Frog (Rana luteiventris); deformities; Diseases and pests; Dispersal; Extremities (Anatomy); Frogs; Fundamental and applied biological sciences. Psychology; grenouille maculée du Columbia (Rana luteiventris); Health aspects; Host parasite relation; pathogenicity; Host-parasite relationships; Invertebrates; Lakes; Larvae; malformations; Nemathelminthia. Plathelmintha; Pacific Chorus Frog (Pseudacris regilla); Parasites; Physiological aspects; Platyhelminthes; Pseudacris regilla; rainette du Pacifique (Pseudacris regilla); Rana luteiventris; Reptiles & amphibians; Ribeiroia ondatrae; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; Worms; United States; British Columbia; North America; America; Canada; United States > US; Canada, British Columbia; Plathelmintha; Amphibia; Parasite; Host; Zoopathogen; Trematoda; Leg(animal); Vertebrata; Animal community; Seasonal variation; Pathogenic; Helmintha; Development; Anomaly; Invertebrata
• ISSN: 1480-3283; 0008-4301; 1480-3283; 0008-4301
• DOI: 10.1139/z2012-050

A parasitic flatworm (Ribeiroia ondatrae Price, 1931) is known to cause severe limb abnormalities and high mortality levels in American amphibian populations. The distributional pattern of this parasite—its main dispersal agent being birds—correlates with the boundaries of migratory flyways in the USA. Yet thus far, R. ondatrae have not been found in Canadian amphibians, which is surprising, considering that said flyways extend well into northern Canada. In this study, we report on a lake in British Columbia that is known to support amphibians with abnormalities similar to those induced by R. ondatrae. To determine if the parasite was present and if it was the cause of the abnormalities, we collected and necropsied metamorphs of the Columbia Spotted Frog (Rana luteiventris Thompson, 1913) and the Pacific Chorus Frog (Pseudacris regilla (Baird and Girard, 1852)), and we set up field enclosures to protect larvae from R. ondatrae. Abnormality levels were high in both species (>20%), with the vast majority being found in close proximity to the metacercariae of R. ondatrae. Moreover, the types of abnormalities closely matched those previously recorded in field and laboratory exposures of amphibians to R. ondatrae. Finally, larvae that developed in the same lake, but were protected from R. ondatrae by an enclosure, did not develop abnormalities. Collectively, these results demonstrate that R. ondatrae are both present in an amphibian community in Canada and responsible for causing limb abnormalities.