Multigeneration assessment of nonylphenol and endosulfan using a model Australian freshwater fish, Melanotaenia fluviatilis

Changes over two generations in offspring and reproductive ability were recorded in crimson-spotted rainbowfish (Melanotaenia fluviatilis), a model Australasian freshwater fish, following a 24 h exposure to nominal nonylphenol concentrations of 50, 100, 500, 1000, 2250, and 5000 g/L and following a 4 h exposure to nominal endosulfan concentrations of 1.0, 5.0, 10, 22, 33, and 50 g/L. There were also four replicated control treatments: control 1 and 2 and solvent control 1 and 2, as well as positive female and male controls: 1 g/L estradiol 1 and 2 and 1 g/L testosterone 1 and 2. Results suggested that there may be some parental transfer of toxicants to embryos even over this short exposure period. Fertility of M. fluviatilis was reduced by a 24 h pulse exposure of adults to 100 g/L nonylphenol and a 4 h exposure to 1.0 g/L endosulfan. Hatch rates were significantly reduced after exposure to nonylphenol, endosulfan, and estradiol control but not in solvent controls and testosterone control. Significant correlations were found between reproductive and physiological parameters for nonylphenol and endosulfan exposed F0 adult rainbowfish. The major reproductive effects were on hatchability of the F1 generation and the gonadosomatic indices of male F1. The respective nominal NOEC and LOEC's for nonylphenol were 50 and 100 g/L, and for endosulfan were <1.0 and 1 g/L. These observed effects have the potential to significantly impact exposed rainbowfish populations through the observed 45% reduction of hatchability and thus larval production. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.