Skip to main content
U.S. flag

An official website of the United States government

Extreme arsenic and antimony uptake and tolerance in toad tadpoles during development in highly contaminated wetlands

May 29, 2020

The effects of extreme concentrations of toxic metalloids, such as arsenic (As) and antimony (Sb), on larval amphibians are not well-understood. We sampled Western Toad tadpoles (Anaxyrus boreas) living in As- and Sb-contaminated wetlands throughout their development. Although the tadpoles completed metamorphosis, they accumulated among the highest concentrations of As and Sb ever reported for a living vertebrate (3866.9 mg/kg; 315.0 mg/kg (dry weight), respectively). Ingestion of contaminated sediment had a more important role in metalloid accumulation than aqueous exposure alone. Metalloids were initially concentrated in the gut; however, by metamorphosis, the majority were found in other tissues. These concentrations subsequently decreased with the onset of metamorphosis, yet remained quite elevated. Sublethal effects, including delayed development and reduced size at metamorphosis, were associated with elevated metalloid exposure. The presence of organic arsenicals in tadpole tissues suggests they have the ability to biomethylate inorganic As compounds. The arsenical trimethyl arsine oxide accounted for the majority of extractable organic As, with lesser amounts of monomethylarsonic acid and dimethylarsinic acid. Our findings demonstrate remarkable tolerance of toad tadpoles to extreme metalloid exposure and implicate physiological processes mediating that tolerance.

Citation Information

Publication Year 2020
Title Extreme arsenic and antimony uptake and tolerance in toad tadpoles during development in highly contaminated wetlands
DOI 10.1021/acs.est.0c00558
Authors Meghan A. Dovick, Thomas R Kulp, Robert Arkle, David Pilliod
Publication Type Article
Publication Subtype Journal Article
Series Title Environmental Science and Technology
Series Number
Index ID 70219551
Record Source USGS Publications Warehouse
USGS Organization Forest and Rangeland Ecosystem Science Center