Exposure to the antifouling chemical medetomidine slows development, reduces body mass, and delays metamorphosis in wood frog (Lithobates sylvaticus) tadpoles
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Antifouling chemicals have a long history of causing toxicity to aquatic organisms. We measured growth and developmental timing in wood frog tadpoles exposed to the antifouling chemical medetomidine (10 nM–10 μM) starting at two different developmental stages in static renewal experiments. For tadpoles hatched from egg masses and exposed for 3 weeks to 100 nM and 1 μM, head width/total body length ratio was significantly shorter compared to control. For field-collected tadpoles at Gosner stage 24–25 and exposed for 2 weeks, 1 and 10 μM medetomidine significantly slowed development as measured by Gosner stage. Medetomidine (1 and 10 μM) significantly increased the time to metamorphosis by over 16 days on average, and at 100 nM and 1 μM, it significantly decreased mass at metamorphosis. We discuss the possible effects of antifouling chemicals containing medetomidine on globally threatened groups such as amphibians.
KeywordsEcotoxicology Amphibians Medetomidine Tadpole Metamorphosis Aquatic
We thank K. Hiraizumi for statistical advice and two anonymous reviewers for helpful comments.
Compliance with ethical standards
The collection and use of all animals was approved by the Institutional Animal Care and Use Committee (IACUC) of Gettysburg College.
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