| Nonylphenol (NP) is the final degradation product of alkylphenol polyethoxylates (APE), which are widely present in plastics, papers, pulp, detergents, pesticides, herbicides, paints and cosmetics. They usually enter aquatic ecosystems primarily via wastewater and are eventually converted to NP, which is resistant to biodegradation. The toxic effects of NP on rosy barb sperm, FG cell line, adult rosy barb and its embryos has been investigated in this study.Firstly, the acute cytotoxicity of NP to the sperm of rosy barb (Puntius conchonius) was tested. It was found that: (1) The motility of sperm exposed to NP (2, 4, 8, 16 and 32μmol/L) was reduced significantly. In addition, the toxicity of NP to rosy barb sperm were both dose-dependent and exposure time-dependent. (2) The ultrastructures of the sperm were also impaired by NP, as evidenced by dilation of mitochondria, dissolved mitochondrial cristae, wrinkled or dissolved of cell membranes. These suggest that mitochondria localized around the mid-piece of sperm may be the primary target of NP toxicity. In addition, we show that rosy barb sperm is a good candidate system for evaluation of NP acute toxicity.Secondly, The FG cell line derived from the gill of flounder Paralichthys. olivaceus was used in the present study to determine the acute cytotoxic effects of NP. Results showed that: (1) The cell growth rate was reduced by NP at concentrations from 10 to 40μmol/L. (2) The antioxidant enzyme activities in FG cells exposed to 40μmol/L NP are reduced within 4-6 h, and O2- content in the NP-exposed cells is increased. (3) The ultrastructures of the NP-exposed cells were altered as evidenced by dissolved mitochondrial cristae, disassociation of RER ribosomes, dilation of RER membranes and increased number of lysosomes. It is proposed that the reduction in antioxidant enzyme activities leads to accumulation of ROS, which in turn results in the damage of mitochondrial infrastructures and decline in energy production, which...
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