SREL Reprint #3572

Acute toxicity of copper to the larval stage of three species of ambystomatid salamanders

Scott M. Weir1,2, Shuangying Yu1,3, David E. Scott1, and Stacey L. Lance1

1Savannah River Ecology Laboratory, University of Georgia, Aiken, SC, USA
2Department of Biology, Queens University of Charlotte, Charlotte, NC, USA
3Sciences Division, Central Piedmont Community College, Charlotte, NC, USA

Abstract: Copper (Cu) appears to be consistently more toxic to anuran species relative to other vertebrate taxa. There are limited Cu toxicity data for salamanders; of the few studies conducted on salamanders, most examined Cu effects on the embryonic, but not the larval, stage. We performed acute toxicity experiments, to quantify LC50s, on Harrison stage 46 larvae (free swimming hatchlings with egg yolk completely absorbed) of three ambystomatid salamander species. Each LC50 experiment used exposure concentrations of 10, 20, 30, 40, 50, and 60 µg/L with 10 replicates per concentration each containing one larva. We found very high toxicity for all species compared to previously published research on the embryo stage. Specifically, the 4-d LC50s for Ambystoma tigrinum and A. opacum were 35.3 and 18.73 µg/L, respectively. The same Cu concentrations caused similar toxicity to A. talpoideum (LC50 = 47.88 µg/L), but exposures required up to 48 d to elicit the same level of mortality. A time-to-event analysis indicated that time to mortality was significantly affected by Cu concentration. Additionally, for A. talpoideum, we observed that elevated levels of Cu decreased growth rate. Comparisons with previously reported Cu toxicity for embryos suggest that, as with fish, Cu may be more toxic to larval salamander stages than for embryos. Further, our data suggest that Cu is an important environmental contaminant that deserves increased scrutiny on the potential for population-level effects where contamination has occurred in wetlands and streams inhabited by salamanders.

Keywords: Amphibians; Metals; Mortality; LC50; Caudata; Sublethal effect

SREL Reprint #3572

Weir, S. M., Shuangying Yu, D. E. Scott, and S. L. Lance. 2019. Acute toxicity of copper to the larval stage of three species of ambystomatid salamanders. Ecotoxicology 28(9): 1023-1031.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).