The toxicity of copper to crucian carp ( Carassius carassius) in soft water

• Published in: The Science of the total environment Vol. 384; no. 1; pp. 239 - 251
• Main Authors: Schjolden, Joachim, Sørensen, Jørgen, Nilsson, Göran E., Poléo, Antonio B.S.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier B.V 01.10.2007; Elsevier Science
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Applied ecology; Biological and medical sciences; Carassius carassius; Carps - metabolism; Carps - physiology; Copper - toxicity; Crucian carp; Crucian carp has a relatively high tolerance to copper; Ecotoxicology, biological effects of pollution; Fresh Water - chemistry; Fresh water ecosystems; Fundamental and applied biological sciences. Psychology; General aspects; Gill morphology; Gills - metabolism; Ion regulation; Oxygen - metabolism; Respiration; Respiration - drug effects; Species Specificity; Synecology; Toxicity Tests; Water Pollutants, Chemical - toxicity; Gill morphology; Carassius carassius; Crucian carp; Copper toxicity; Ion regulation; Crucian carp has a relatively high tolerance to copper; Respiration; Gill; Ecotoxicology; Ionic regulation; Toxicity; Heavy metal; Freshwater environment; Aquatic environment; Vertebrata; Pisces; Morphology; Copper
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2007.06.009

Crucian carp ( Carassius carassius) were exposed to a Cu rich medium (pH 6.6, conductivity 25 μS/cm, 2.91 mg Ca 2+/l, approximately 300 μg Cu 2+/l). Untreated department water (pH 6.6, conductivity 25 μS/cm, 2.91 mg Ca 2+/l) acted as control. Mortality in crucian carp was first observed after 13 days of exposure to the Cu rich medium. There were, however, significant changes in haematocrit, plasma chloride, plasma sodium and water content in muscle in fish exposed to the Cu rich medium after two days. After 14 days of exposure to copper, haematocrit increased to 52 ± 2% (control: between 37 and 40%), plasma chloride decreased to 45 ± 5 mmol/l (control: 99–106 mmol/l), plasma sodium decreased to 81 ± 6 mmol/l (control: 116–137 mmol/l), and water content in muscle increased to 83.0 ± 0.3% (control: 78.7–79.9%). No apparent changes in blood ethanol, and minor changes in plasma lactate were observed in copper exposed fish. Analyses of the gills revealed an increasing concentration of copper on the gills from fish exposed to Cu rich water. After 14 days, the concentration of copper accumulated in the gill was 12.8 ± 4.1 μg Cu/g wet weight (control: 0.91–1.19 μg Cu/g wet weight). A reduction of the respiratory area in fish exposed to copper was observed, in terms of both lamellar and filamental fusion. The normoxic O 2 uptake did not change, but the critical oxygen tension was elevated to 6.12 ± 1.04 mg O 2/l after a 6 day exposure to copper (control: 1.03 ± 0.05 mg O 2/l). This study shows that crucian carp has a higher tolerance to copper compared to other freshwater fish species. Our results suggest that this tolerance is based on the ability of crucian carp to avoid becoming hypoxic as well as an extreme tolerance to severe loss of plasma ions.