title: Contrasting effects of chloride on growth, reproduction, and toxicant sensitivity in two genetically distinct strains of Hyalella azteca.
abstract: The strain of Hyalella azteca (Saussure: Amphipoda) commonly used for aquatic toxicity testing in the United States has been shown to perform poorly in some standardized reconstituted waters frequently used for other test species. In 10-d and 42-d experiments, the growth and reproduction of the US laboratory strain of H. azteca was shown to vary strongly with chloride concentration in the test water, with declining performance observed below 15 mg/L to 20 mg/L. In contrast to the chloride-dependent performance of the US laboratory strain of H. azteca, growth of a genetically distinct strain of H. azteca obtained from an Environment Canada laboratory in Burlington, Ontario, Canada, was not influenced by chloride concentration. In acute toxicity tests with the US laboratory strain of H. azteca, the acute toxicity of sodium nitrate increased with decreasing chloride in a pattern similar not only to that observed for control growth, but also to previous acute toxicity testing with sodium sulfate. Subsequent testing with the Burlington strain showed no significant relationship between chloride concentration and the acute toxicity of sodium nitrate or sodium sulfate. These findings suggest that the chloride-dependent toxicity shown for the US laboratory strain may be an unusual feature of that strain and perhaps not broadly representative of aquatic organisms as a whole.
authors.affiliation: Illinois Natural History Survey, Champaign, Illinois, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Soucek
authors.affiliation: Mid-Continent Ecology Division, US Environmental Protection Agency, Duluth, Minnesota, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Mount
authors.affiliation: Illinois Natural History Survey, Champaign, Illinois, USA.
authors.forename: Amy
authors.initials: A
authors.lastname: Dickinson
authors.affiliation: Mid-Continent Ecology Division, US Environmental Protection Agency, Duluth, Minnesota, USA.
authors.forename: J Russell
authors.initials: JR
authors.lastname: Hockett
authors.affiliation: Illinois Natural History Survey, Champaign, Illinois, USA.
authors.forename: Abigail R
authors.initials: AR
authors.lastname: McEwen
mesh_terms: D033304:Amphipoda / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development*; D000818:Animals; D002712:Chlorides / Q000633:toxicity*; D009566:Nitrates / Q000633:toxicity; D012098:Reproduction / Q000187:drug effects; D013431:Sulfates / Q000633:toxicity; D023382:Toxicity Tests, Acute; D014481:United States; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D002712:Chlorides; D009566:Nitrates; D013431:Sulfates; D014874:Water Pollutants, Chemical; C012036:sodium sulfate; C031618:sodium nitrate
keywords: Chloride; Genetic strain; Hyalella azteca; Nitrate; Toxicity testing