Effects of short-chain chlorinated paraffins on feeding, oxidative status, and multigenerational parameters in the water flea Moina macrocopa

Abstract

Despite being persistent pollutants of global concern and frequently detected in aquatic environments, the detrimental effects of short-chain chlorinated paraffins (SCCPs) on aquatic crustaceans remain limited. Here, we analyzed the acute and chronic effects of SCCPs on the freshwater flea Moina macrocopa. The no observed effect concentration (NOEC) value of SCCPs for 48 h was determined to be 0.24 μg L⁻¹, while the 10 % (LC10) and 50 % (LC50) lethality values were measured as 3.7 and 36 μg L⁻¹, respectively. In the acute exposure experiment, exposure to the LC10 value of SCCPs reduced feeding performance, acetylcholinesterase activity, and thoracic limb movement. In response to the LC10 value, reactive oxygen species levels increased, accompanied by elevated concentrations of malondialdehyde and glutathione. Enzymatic activities of glutathione S-transferase, catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase were significantly elevated at the LC10 value, indicating active involvement of the antioxidant defense system in mitigating oxidative stress. Long-term exposure to the 1/10 NOEC and NOEC values across three generations showed multigenerational detrimental impacts of SCCPs, including reductions in survival, growth, and reproduction in the second and/or third generations. Taken together, our results suggest that even sublethal concentrations of SCCPs can acutely induce cholinergic impairment and oxidative stress, while chronically impairing population maintenance in M. macrocopa.