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Contaminant effects on host‐parasite interactions: atrazine, frogs, and trematodes
Author(s) -
Koprivnikar Janet,
Forbes Mark R.,
Baker Robert L.
Publication year - 2007
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1897/07-220.1
Subject(s) - atrazine , parasite hosting , host (biology) , biology , ecology , zoology , pesticide , world wide web , computer science
The effects of contaminants on multispecies interactions can be difficult to predict. The herbicide atrazine is commonly used in North America for corn crops, runs off into wetlands, and has been implicated in the increasing susceptibility of larval frogs to trematode parasites. Using experimental challenges with free‐living stages of trematodes (cercariae), it was found that Rana sylvatica tadpoles exposed to 30 μg/L of atrazine had significantly higher intensity of parasitism than did larval frogs either not exposed or exposed to 3 μg/L of atrazine. This result could not be explained by high concentrations of atrazine diminishing antiparasite behavior of tadpoles. Furthermore, when tadpoles and cercariae both were exposed to the same concentration of atrazine, either 3 or 30 μg/L, the abundance of formed cysts was not different from the condition in which both were housed at 0 μg/L of atrazine. Atrazine appears to be debilitating to both free‐living cercariae and tadpoles. Studies examining relations between parasitism and contaminant levels must account for such combined effects as well as influences on other interacting species (e.g., first intermediate snail hosts).