title: The effects of dimethylated and alkylated polycyclic aromatic hydrocarbons on the embryonic development of the Japanese medaka.
abstract: The Japanese medaka (Oryzias latipes) early-life stage assay was used to investigate the effects of a number of commercially available dimethylated polycyclic aromatic hydrocarbons (PAHs) (3,6-dimethylphenanthrene, 7,12-dimethylbenz[a]anthracene, and 4,6-dimethyldibenzothiophene) and their unsubstituted congeners, dimethylated and unsubstituted tertiary mixtures, and a complex environmental mixture (with elevated C2-substituted dibenzothiophene) on embryo larval development. Unsubstituted PAHs showed trends of increased blue sac disease (BSD) relative to dimethylated PAHs, although the severity of BSD induction varied. Results demonstrated that the dibenzothiophene congeners were the strongest inducers of BSD of the commercial PAHs tested. These compounds reduced the hatching success of embryonic medaka, an effect that was enhanced in the mixture. The base neutral extract significantly increased the frequency and severity of BSD abnormalities, while significantly reducing larval hatch length. Based on these results, a sublethal maximum allowable toxicant concentration (MATC) of 13.91 microg PAHs/L was calculated.
authors.affiliation: Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ont., Canada N2L 3G1.
authors.forename: Spencer
authors.initials: S
authors.lastname: Rhodes
authors.forename: Andrea
authors.initials: A
authors.lastname: Farwell
authors.forename: L Mark
authors.initials: LM
authors.lastname: Hewitt
authors.forename: Michael
authors.initials: M
authors.lastname: Mackinnon
authors.forename: D George
authors.initials: DG
authors.lastname: Dixon
mesh_terms: D000818:Animals; D004625:Embryo, Nonmammalian / Q000187:drug effects; D005393:Fish Diseases / Q000139:chemically induced* / Q000196:embryology / Q000473:pathology; D005399:Fishes; D007814:Larva / Q000187:drug effects; D009990:Oryzias; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry / Q000633:toxicity*; D013876:Thiophenes / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D013876:Thiophenes; D014874:Water Pollutants, Chemical; C016366:dibenzothiophene