Effects of elevated temperature on the toxicity of copper and oxytetracycline in the marine model, Euplotes crassus: A climate change perspective

• Published in: Environmental pollution (1987) 2014-11, Vol.194, p.262-271
• Main Authors: Gomiero, A., Viarengo, A.
• Format: Article
• Language: English
• Subjects: Agnatha. Pisces; Animal, plant and microbial ecology; Animals; Antibiotics; Applied ecology; Biological and medical sciences; Biomarkers; Climate Change; Contaminants; Copper; Copper - toxicity; Drugs; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on vertebrates; Euplotes - drug effects; Euplotes - physiology; Euplotes crassus; Fundamental and applied biological sciences. Psychology; Hot Temperature; Mixtures; Oxytetracycline; Oxytetracycline - toxicity; Pollutant's temperature related toxicity; Protozoa; Survival; Thermal stress; Toxicity; Water Pollutants, Chemical - toxicity
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2014.07.035

Trace metals and broad-spectrum antibiotic drugs are common environmental contaminants, the importance of which is increasing due to global climate change-related effects. In the present study, the biological model organism E. crassus was first acclimated to five temperatures, from 25 °C to 33 °C, followed by exposure to nominal concentrations of copper, the antibiotic model compound oxytetracycline and mixtures of both, at increasing thermal conditions. Variations of temperature-related toxicity were assessed by two high-level endpoint tests, survival and replication rates, and two sublethal parameters: endocytosis rate and lysosomal membrane stability. The selected toxicants presented opposite behaviours as the protozoa's survival rates increased following an increasing thermal gradient in the oxytetracycline-related treatments, and a decline of tolerance in metal-related treatments was observed. Results of tests combining binary mixtures of tested toxicants showed a complex pattern of responses. •Copper (Cu) and oxytetracycline (OTC) temperature related toxicity was assessed.•The selected toxicants presented opposite behaviours.•Survival rates increased in OTC treatments, while a decrement was observed for Cu.•Results of tests combining binary mixtures showed a complex pattern of responses.•This study underlines a potential global warming-related risk for aquatic organisms. Variations in temperature-related toxicity of Cu and the antibiotic oxytetracycline were assessed via a variety of tests. The selected toxicants presented opposite behaviours.