Abstract:Sediment toxicity tests using benthic invertebrates can provide important evidence in the assessment of sediment quality. Bellamya aeruginosa is widely distributed as a dominant community member in aquatic ecosystems in China. In this study, adult B. aeruginosa from lab cultures were exposed for 42 d to sediments artificially spiked with lead (Pb) at environmentally relevant concentrations (39-433 μg g-1) to evaluate their reproductive reaction and sensitivity of oxidative stress responses. The results showed that no reproductive toxicity was observed at relatively low Pb concentrations, whereas the fecundity was decreased significantly by 246μg Pb g-1 or above. A relatively low Pb concentration (66μg g-1) led to significantly increased hepatopancreatic SOD and CAT activities with obvious differences between sexes: the oxidative stress responses of males to lead exposure were more sensitive than that of females. A high Pb concentration (433μg g-1) caused damage to the antioxidases. In contrast, glutathione (GSH) contents were only decreased significantly by the highest Pb concentration. The reproductive response of B. aeruginosa was indicative of the chronic toxicity of sediments moderately contaminated by Pb. While GSH was insensitive to the chronic stress of low concentrations of sedimental Pb, hepatopancreatic SOD and CAT, especially in males, were potentially effective biomarkers indicating the chronic stress of low concentrations of sedimental Pb.