M9 PM Multiple Stressors in Amphibian and Reptile Ecotoxicology
Monday, 14 November 2005: 1:50 PM - 5:30 PM in 339-340

(CHE-1117-573757) Effects of chronic exposure of cadmium and lead on amphibian adults.

Karasov, W¹, Gross, J^{1, 2}, Chen, T-H¹, ¹ Department of Wildlife Ecology, University of Wisconsin-Madison, Madison, WI, USA² Department of Animal Sciences, University of Wisconsin-Madison, Madison, WI, USA

ABSTRACT- We evaluated the effects of chronic exposure to cadmium and lead in adult northern leopard frogs (Rana pipiens). Frogs were exposed to 10 or 50 g of cadmium or lead per gram of body mass via consumption of heavy metal injected crickets for 15 weeks, and then allowed to hibernate. Feeding behavior, overall health, and mortality were monitored through the exposure period and hibernation. Gonad mass and oocyte profiles were also examined in females exposed to cadmium. Survival was 100% during the oral exposure period. All frogs in the high cadmium group developed abnormal lingual flipping movements, significantly compromising feeding ability. Mortality was observed during hibernation in two cadmium and low lead groups. Edema was only recorded in two cadmium groups. Compared to the controls, females in the high cadmium group had significantly decreased gonad mass and higher proportion of immature and abnormal oocytes. Our study suggests that sublethal level of oral exposure to cadmium may cause negative effects on feeding behaviors, overall health and survival during hibernation, and oogenesis in northern leopard frogs. The sensitivity to cadmium will be compared in adult northern leopard frogs and western clawed frogs (Xenopus tropicalis). [Supported by Sea Grant R/MW-84]

Key words: chronic, cadmium, lead, amphibian