Effects of nonylphenol on the gonadal differentiation of the hermaphroditic fish, Rivulus marmoratus.
Nonylphenol (NP) is an estrogenic degradation product of alkylphenol polyethoxylate surfactants. In this study, the effects of NP on gonadal differentiation and development in Rivulus marmoratus (Osteichthyes, Cyprinodontiformes), a self-fertilizing, hermaphroditic species, were examined. Starting at hatching, fish were exposed to 150 or 300 microg 1(-1) NP (nominal concentrations) in a static system with daily renewal. The measured concentration of NP in the test water decreased rapidly; half-life was 8.0 h. After 60 d of exposure to NP, fish were kept in uncontaminated water for 20 d and were then preserved for histological examination. No fish exposed to 300 microg l(-1) NP (N=8) and only two of nine fish exposed to 150 microg l(-1) NP developed testicular tissue, compared with nine of 13 water-control fish and five of nine solvent-control fish. Oogenesis was also significantly inhibited by NP. None of the fish exposed to 300 microg l(-1) and only two of nine fish exposed to 150 microg l(-1) NP had vitellogenic oocytes, compared with seven of 11 water-control fish (not including males) and six of nine solvent-control fish. Dysplasia of the gonadal lumen also occurred in fish exposed to 300 microg l(-1) NP. These changes, including testicular agenesis, have not been previously reported in fish exposed to NP.
Tanaka
Jennifer N
JN
Southeastern Cooperative Fish Disease Project, Department of Fisheries and Allied Aquacultures, Auburn University, AL 36849, USA.
Grizzle
John M
JM
D000818:Animals; D004305:Dose-Response Relationship, Drug; D004781:Environmental Exposure; D005260:Female; D005399:Fishes / Q000254:growth & development*; D057850:Hermaphroditic Organisms; D008297:Male; D010053:Ovary / Q000187:drug effects / Q000254:growth & development*; D010636:Phenols / Q000009:adverse effects*; D019849:Sex Determination Processes; D012733:Sex Differentiation / Q000187:drug effects*; D013737:Testis / Q000187:drug effects / Q000254:growth & development*; D014818:Vitellogenesis / Q000187:drug effects; D014874:Water Pollutants, Chemical / Q000009:adverse effects*
D010636:Phenols; D014874:Water Pollutants, Chemical; C025256:nonylphenol