title: Metal effects on fathead minnows (Pimephales promelas) under field and laboratory conditions.
abstract: The consequences of low-level metal exposure to early life stages of fathead minnows (Pimephales promelas) were investigated along a contamination gradient near Sudbury, Canada. Field exposures resulted in elevated hatching time and increased mortality in metal-contaminated lakes, in contrast to laboratory exposures where no effects were observed. Dissolved and ionic Cd and Ni were associated with changes in hatching time and larval mortality under field conditions, though other potential contaminants were not examined and may also have had an influence. The increased biological response of field-exposed fish, relative to fish exposed to the same water in laboratory conditions, may be the result of higher stress in natural environments, which could sensitize fish to contaminants. Analysis also indicated that, as contamination increases, the discrepancies between laboratory and field estimates of effect also increase. A temperature versus hatching time relationship was also quantified for fathead minnows.
authors.affiliation: Institut National de la Recherche Scientifique-Eau, Terre et Environnement, Université du Québec, 490 rue de la Couronne, Québec, QC, Canada G1K 9A9. charles_gauthier@ete.inrs.ca
authors.forename: Charles
authors.initials: C
authors.lastname: Gauthier
authors.forename: Patrice
authors.initials: P
authors.lastname: Couture
authors.forename: Greg G
authors.initials: GG
authors.lastname: Pyle
mesh_terms: D000818:Animals; D002104:Cadmium / Q000633:toxicity*; D003530:Cyprinidae / Q000502:physiology*; D005618:Fresh Water / Q000032:analysis; D007814:Larva / Q000187:drug effects; D008018:Life Cycle Stages / Q000187:drug effects*; D009532:Nickel / Q000633:toxicity*; D010063:Ovum / Q000187:drug effects; D013696:Temperature; D018675:Toxicity Tests; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D002104:Cadmium; D009532:Nickel