title: Embryotoxicity of maternally transferred methylmercury to fathead minnows (Pimephales promelas).
abstract: Mercury (Hg) is a ubiquitous environmental contaminant and potent neurotoxin. In aquatic environments, Hg can be transformed into methylmercury (MeHg), which bioaccumulates in aquatic food webs, including fish. Methylmercury has been shown to transfer from female fish to developing eggs; however, relatively little is known regarding the effects of maternally transferred MeHg on fish embryos. The present study evaluated the effects of maternally transferred MeHg on fathead minnow (Pimephales promelas) embryos. Embryos were collected from adult fatheads exposed for 30 d to 1 of 3 diets spiked with MeHg: a control diet (0.02 ppm Hg dry wt), a low diet (0.87 ppm Hg dry wt), or a high diet (5.5 ppm Hg dry wt). No effects on spawning frequency, clutch size, or total egg output were observed. In embryos, Hg concentration was a function of female diet and the duration (number of days) of female exposure. Compared with controls, embryos from the low-diet treatment displayed altered embryonic movement patterns (hyperactivity) and decreased time to hatch. Embryos from the high-diet treatment had delayed hatching and increased mortality compared with the other treatments. Collectively, these results suggest that maternally transferred Hg may impact survival, behavior, and developmental milestones of the embryo-larval stages of fish. Environ Toxicol Chem 2016;35:1436-1441. © 2015 SETAC.
authors.affiliation: Department of Biological Sciences & Institute of Applied Sciences, University of North Texas, Denton, Texas, USA.
authors.forename: Kristin N
authors.initials: KN
authors.lastname: Bridges
authors.affiliation: Department of Biological Sciences & Institute of Applied Sciences, University of North Texas, Denton, Texas, USA.
authors.forename: Brianne K
authors.initials: BK
authors.lastname: Soulen
authors.affiliation: Department of Biological Sciences & Institute of Applied Sciences, University of North Texas, Denton, Texas, USA.
authors.forename: Carmen L
authors.initials: CL
authors.lastname: Overturf
authors.affiliation: University of Michigan Biological Station and School of Natural Resources and Environment, University of Michigan, Ann Arbor, Michigan, USA.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Drevnick
authors.affiliation: Department of Biological Sciences & Institute of Applied Sciences, University of North Texas, Denton, Texas, USA.
authors.forename: Aaron P
authors.initials: AP
authors.lastname: Roberts
mesh_terms: D000818:Animals; D003530:Cyprinidae / Q000196:embryology / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004625:Embryo, Nonmammalian / Q000187:drug effects*; D047108:Embryonic Development / Q000187:drug effects*; D005260:Female; D007814:Larva; D008628:Mercury / Q000633:toxicity*; D008767:Methylmercury Compounds / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D008767:Methylmercury Compounds; D014874:Water Pollutants, Chemical; D008628:Mercury
keywords: Behavioral toxicity; Maternal transfer; Mercury; Neurotoxicity; Reproductive toxicity