The valve movement response of three freshwater mussels Corbicula fluminea Müller 1774, Hyriopsis cumingii Lea 1852, and Anodonta woodiana Lea 1834 exposed to copper

Biological early warning system (BEWS) is an innovative system for real-time water quality monitoring based on different behavioral responses of aquatic organisms. Mussels easily meet the requirement for optimal organisms in BEWS. However, little emphasis has been placed on freshwater mussels. In this study, the Hall element sensor system has been used to investigate exposure–response relationships of valve movement in freshwater Corbicula fluminea, Hyriopsis cumingii, and Anodonta woodiana exposed to a copper (Cu²⁺) gradient of 0, 0.01, 0.1, 1, and 10 mg l⁻¹. The measured behavioral parameters were compared to determine if a response could be elucidated, including the amplitude of valve opening (AVO) and frequency of valve adduction (FVA). The results suggest that the mean AVO was significantly decreased in C. fluminea exposed to 0.1 and 1 mg l⁻¹, and decreased for H. cumingii and A. woodiana after exposure to 10 mg l⁻¹. The mean FVA was significantly decreased in H. cumingii exposed to 1 and 10 mg l⁻¹, while A. woodiana revealed lower frequencies only at 10 mg l⁻¹. The three species showed inherent rhythms of valve movements and dose-dependent responses upon copper exposure, and H. cumingii showed the most obvious profile of a copper dose-valve movement response.