2,4-Dichlorophenoxyacetic acid containing herbicide impairs essential visually guided behaviors of larval fish

Effects of Low, Subchronic Exposure of 2,4‐Dichlorophenoxyacetic Acid (2,4‐d) and Commercial 2,4‐d Formulations on Early Life Stages of Fathead Minnows (Pimephales promelas)

“…In addition to possible endocrine disruption, Dehnert et al (2018) suggested another possible hypothesis for the impacts of 2,4-D formulations on fathead minnow larval survival in that exposure to 2,4-D may increase oxidative stress; 2,4-D moieties have been shown to increase such stress in previous peer-reviewed literature (Oruc et al 2004;Atamaniuk et al 2013;Li et al 2017). Most recently, we found that 2,4-D at concentrations below putative NOECs alters the development and function of neural circuits underlying vision of larval zebrafish (Danio rerio), and thereby reduces visually guided behaviors essential to survival (Dehnert et al 2019). Even without an adequate explanation for the Dehnert et al (2018) results, it would be irresponsible to ignore the results concerning the use of 2,4-D for aquatic weed control.…”

“…The 2005 USEPA reregistration eligibility decision explicitly stated that there was limited literature on the effects of low-level chronic 2,4-D exposure on fish. In the past 3 yr, DeQuattro and Karasov (2016) and Dehnert et al (2018Dehnert et al ( , 2019 have all now reported declines in survival, starting as early as 6 d post fertilization in larval fish after exposure to 2,4-D concentrations below the previously presumed NOECs (US Environmental Protection Agency 2005). Moreover, other researchers have shown impacts on growth, acetylcholinesterase activity, and metabolic parameters at 2,4-D concentrations below presumed NOECs (0.10-10 ppm; Xie et al 2005;da Fonseca et al 2008;Menezes et al 2015).…”

Approaches to Test the Neurotoxicity of Environmental Contaminants in the Zebrafish Model: From Behavior to Molecular Mechanisms

“…In addition, retinal toxicity of nicotinamide phosphoribosyl transferase inhibitors, which are promising antitumor drug candidates, could be predicted in zebrafish larvae (Cassar et al 2017). Phototaxis has been used to demonstrate impairments in visually guided behavior following exposure to 2,4‐dichlorophenoxyacetic acid, an active ingredient in commercial herbicide formulations (Dehnert et al 2019).…”

“…In contrast, widespread suppression of neuronal activity was found after treatment with the sodium channel–blocking anesthetic tricaine mesylate (Randlett et al 2015). Moreover, exposure to 2,4‐dichlorophenoxyacetic acid, an ingredient of commercial herbicide formulations, resulted in impaired visually guided behaviors and reduced activity in the neuronal circuits underlying prey detection (Dehnert et al 2019).…”

Exploring the Impacts of Methylmercury‐Induced Behavioral Alterations in Larval Yellow Perch in Lake Michigan Using an Individual‐Based Model

“…For example, contaminants can impair the olfactory sensory system (Sakamoto et al 2016), which in turn may lead to a reduction in swimming activity and food intake (Puglis et al 2019). Additionally, impairments of the neural circuits mediating vision following contaminant exposure can lead to lower larval fish prey capture rates and subsequently impact growth (Dehnert et al 2019). Furthermore, alterations in motor responses used to detect and assess potential threats (i.e., predators) can occur following sublethal contaminant exposures (Lovato et al 2016), which would reduce an individual’s chance at surviving early life stages.…”