ARS | Publication request: Malformation, Mortality and Parasites in Northern Leopard Frogs in MN and Nd.

Submitted to: Minnesota Water Abstracts
Publication Type: Abstract
Publication Acceptance Date: January 1, 2002
Publication Date: April 17, 2002
Citation: Shappell, N.W., Gackle, N.J., Canfield, J., Sutherland, D. 2002. Malformation, mortality and parasites in northern leopard frogs in MN and ND. [abstract]. Minnesota Water 2002 Conference, April 17-20, 2002, St. Cloud, MN.

Technical Abstract: In 2000 a field study compared the relative incidence of mortality and malformation of developing northern leopard frogs (Rana pipiens) at two Minnesota (MN)lake sites, one site with history of high incidence of malformations (CWB)and one with low incidence (BUT). Tadpoles were reared in enclosures at these sites, a ND site, and in the lab. Mortality was high initially at both MN sites, with tadpoles from BUT carrying infectious disease. Malformations and mortality were found at CWB in free-ranging tadpoles and frogs, yet only one froglet from enclosures was malformed (BUT). In parasite evaluation, free-ranging froglets had higher burdens than enclosure-reared froglets. Riberoia, the parasite capable of causing limb malformation in Pacific tree frogs, was found at a higher incidence in free-ranging frogs from CWB and a Hibbing site with high incidence of malformation than frogs from BUT. Overall survival of MN-reared tadpoles to successful forelimb emergence was ~2%. In 2001 a second field study compared parasite burden and health of native frogs relative to land use in ND and MN. No significant mortality was seen at the 20 sites monitored. Frogs were surveyed and a sub-sample necropsied. There were no correlations between land use, parasite burden, or malformations. Ribeiroia was found in high frequency only at the CWB and Hibbing sites.