Physiological performance of common carp (Cyprinus carpio, L., 1758) exposed to a sublethal copper/zinc/cadmium mixture

• Published in: Comparative biochemistry and physiology. Toxicology & pharmacology 2021-04, Vol.242, p.108954, Article 108954
• Main Authors: Pillet, M., Castaldo, G., Rodgers, E.M., Poleksić, V., Rašković, B., Bervoets, L., Blust, R., De Boeck, G.
• Format: Article
• Language: English
• Subjects: Aerobic scope; Bioaccumulation; Gill histology; Metal; Mixture stress; Temperature
• ISSN: 1532-0456; 1878-1659
• DOI: 10.1016/j.cbpc.2020.108954

In a natural ecosystem, fish are subjected to a multitude of variable environmental factors. It is important to analyze the impact of combined factors to obtain a realistic understanding of the mixed stress occurring in nature. In this study, the physiological performance of juvenile common carp (Cyprinus carpio) exposed for one week to an environmentally relevant metal mixture (4.8 μg/L of copper; 2.9 μg/L of cadmium and 206.8 μg/L of zinc) and to two temperatures (10 °C and 20 °C), were evaluated. After 1, 3 and 7 days, standard (SMR) and maximum metabolic rate (MMR) were measured and aerobic scope (AS) was calculated. In addition, hematocrit, muscle lactate, histology of the gills and metal accumulation in gills were measured. While SMR, MMR and AS were elevated at the higher temperature, the metal mixture did not have a strong effect on these parameters. At 20 °C, SMR transiently increased, but no significant changes were observed for MMR and AS. During metal exposure, hematocrit levels were elevated in the 20 °C group. The bioaccumulation of Cd in the gills reflected the increased metabolic rate at the higher temperature, with more accumulation at 20 °C than at 10 °C. Anaerobic metabolism was not increased, which corresponds with the lack of significant histopathological damage in the gill tissue. These results show that common carp handled these metal exposures well, although increased temperature led to higher Cd accumulation and necessitated increased hematocrit levels to maintain aerobic performance. [Display omitted] •Common carp is able to cope with short term exposure to Cu/Cd/Zn metal mixture.•Metal mixture has an effect on physiological performance only at the higher temperature (20 °C).•Standard metabolic rate of common carp is increased after 3 days of exposure to metal mixture at 20 °C.•Facing metal mixture at environmental concentration, common carp anaerobic metabolism is not induced.