PM11 Wildlife Ecotoxicology
Exhibit Hall
8:00 AM - Monday
(PM186) Developmental instability (DI) in Rana pipiens and Rana clamitans from Horicon National Wildlife Refuge (HNWR).
Gross, J1, Chen, T1, Prahl, L1, Karasov, W1, 1 University of Wisconsin, Madison, Wisconsin, United States
ABSTRACT- Stress factors in ecological systems have been shown to alter growth and development in species. With increased environmental stress or decreased species health there exists a need to monitor the level of DI in populations. Studies report prior to population declines that levels of DI increases. HNWR receives water from the Rock River and surrounding uplands. Assessment plans have reported high concentrations of heavy metals in marsh sediments. This study investigates levels of DI in R. pipiens and R. clamitans from HNWR. The degree of asymmetry in bilateral structures (femur, tibia-fibula and radio-ulna) was measured in recently metamorphosed frogs. Forty-one green and thirty-seven leopard frogs, collected from five sites, were measured blind and independently for five traits (n=3 measures per structure). R. pipiens exhibited significant (P < 0.05) DI for femur at 3 of 4 sites, for tibia-fibula at 2 of 4 sites and at 1 of 4 sites (P < 0.1) for radio-ulna. R. clamitans exhibit DI for femur (P < 0.05) at 2 of 4 sites, and for tibia-fibula at 2 of 4 sites. Significant levels of directional asymmetry (DA) were found for R. pipiens at 1 of 4 sites for femur and at 2 of 4 sites for tibia-fibula (P < 0.05). DA was found at 3 of 4 sites (P < 0.05 at 2 of 3 sites and P < 0.1 at 1 of 3 sites) for tibia-fibula and 1 of 4 sites (P < 0.1) for radio-ulna. Fluctuating asymmetry + antisymmetry were significantly different among sites for femur in R. pipiens (P < 0.01) and for tibia-fibula in R. clamitans (P < 0.1). Levels of DI were site specific for both species and predominately existed in hind limb bones. [Supported by the Zoological Society of Milwaukee]
Key words: development, amphibians, fluctuating asymmetry