Meeting Abstract

P1.22  Jan. 4  Nonrandom trematode (Echinostoma trivolvis) infection in experimentally paired amphibian species assemblages CHAMBERS, D.L.*; BELDEN, L.K.; Virginia Tech; Virginia Tech dlchamb@vt.edu

Due to an established link between many amphibian deformities and infection with the parasitic trematode, Ribeiroia ondatrae, there is growing interest in the impact of parasitic infection in amphibians. However, we still have a poor understanding of how biotic and abiotic factors can influence infection rates in larval amphibians. To examine how the presence of multiple amphibian species influences trematode infection rates in focal Rana sp. tadpoles, we utilized four species of amphibians (Rana clamitans, R. sylvatica, Hyla versicolor, and Ambystoma jeffersonianum) that are sympatric with the trematode Echinostoma trivolvis. In laboratory trials, we paired species that overlap in development time; R. clamitans was paired with H. versicolor and R. sylvatica was paired with A. jeffersonianum. Amphibian larvae (5 of each of the two species being tested) were placed in tubs and 200 E. trivolvis cercariae were added. After 72 h, larvae were collected and dissected to determine infection levels. The mean number of metacercarial cysts was significantly higher in H. versicolor (4.56 � 0.64) than in R. clamitans (2.00 � 0.42), and higher in R. sylvatica (12.62 � 0.62) than in A. jeffersonianum (0.71 � 0.15). This suggests that cercarial encystment likely occurs nonrandomly between amphibian species within the same habitat and that the presence of multiple larval amphibian species may alter infection risk for Rana sp. tadpoles.