Exposure to the antifouling chemical medetomidine slows development, reduces body mass, and delays metamorphosis in wood frog ( Lithobates sylvaticus) tadpoles

摘要

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.