title: Decline in reproductive success, sex reversal, and developmental alterations in Japanese medaka (Oryzias latipes) after continuous exposure to octylphenol.
abstract: Japanese medaka (Oryzias latipes) were continuously exposed to concentrations of 0, 2, 20, and 50 microg/L octylphenol, 0.01 per thousand dimethyl sulfoxide, and 100 ng/L 17beta-estradiol from 2 to 4 h postfertilization until maturity. Exposure to > or =2 microg/L octylphenol caused a 20-30% increase in mortality both before and after hatch. Growth was significantly decreased in fish exposed to 50 microg/L octylphenol and in the positive control. Sex ratio changed from 42:58 (females:males) in controls to 57:40 at 50 microg/L octylphenol, and 3 and 4% of the medaka exposed to 50 microg/L octylphenol and 17beta-estradiol developed testes-ova. In cross-mating experiments, mating of exposed males with control females resulted in an up to 11% lower fertilization rate than in controls. Results indicate that continuous exposure to octylphenol causes a broad variety of reproductive effects, which can be correlated with the xenoestrogenic potential of octylphenol.
authors.affiliation: Aquatic Ecology and Toxicology Group, Department of Zoology I, University of Heidelberg, Im Neuenheimer Feld 230, D-69120 Heidelberg, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Knörr
authors.forename: Thomas
authors.initials: T
authors.lastname: Braunbeck
mesh_terms: D000014:Abnormalities, Drug-Induced; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004968:Estrogens, Non-Steroidal / Q000633:toxicity*; D005260:Female; D006066:Gonads / Q000002:abnormalities / Q000187:drug effects; D057850:Hermaphroditic Organisms; D008136:Longevity / Q000187:drug effects; D008297:Male; D009990:Oryzias / Q000502:physiology*; D010636:Phenols / Q000633:toxicity*; D012098:Reproduction / Q000187:drug effects* / Q000502:physiology; D019849:Sex Determination Processes; D012744:Sex Ratio
chemical_list: D004968:Estrogens, Non-Steroidal; D010636:Phenols; C080417:4-octylphenol