Combined toxic effects of nitrite and ammonia on life history traits of Daphnia pulex

Nitrite and ammonia are two of the most common toxic nitrogenous pollutants in aquatic ecosystem, which can pose a serious threat to health organisms. Cladocerans, as an important part freshwater will inevitably be harmed by these pollutants. To evaluate combined effects on cladocerans, we simulated 15 combinations five nitrite concentrations (0, 0.5, 2, 4, 8 mg L −1 ) three 0.1, 1 study changes life history traits Daphnia pulex exposed for 21 days. Results showed that under stress ammonia, survival time D. was shortened, first batch eggs brood were delayed, body size tail spine length at maturation reduced, total offspring number broods decreased. There some synergistically negative between The presence reduced tolerance nitrite, vice versa . These findings provided new insights into great significance understanding population dynamics specific species cladocerans community condition compound