Differential sensitivity to the antifouling chemical medetomidine between wood frog and American toad tadpoles with evidence for low-dose stimulation and high-dose inhibition of metamorphosis.

Antifouling chemicals are legacy contaminants in aquatic ecosystems. Previous experiments have shown that a 14-day exposure to the antifouling chemical medetomidine delays metamorphosis and reduces body mass in wood frog tadpoles. In the present study, we exposed wood frog tadpoles to medetomidine for 3, 7, and 10 days at 100 nM, 1 μM, and 10 μM.

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

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.

Exposure to SSRI-type antidepressants increases righting time in the marine snail Ilyanassa obsoleta.

Exposure to human antidepressants has been shown to disrupt locomotion and other foot-mediated mechanisms in aquatic snails. We tested the effect of three selective serotonin reuptake inhibitor (SSRI)- and one selective serotonin-norepinephrine reuptake inhibitor (SNRI)-type antidepressants on the righting response in the marine snail, Ilyanassa obsoleta. All four antidepressants (fluoxetine, sertraline, paroxetine, venlafaxine) significantly increased righting time compared with controls with an exposure time as short as 1 h.