The combined effect of copper and low pH on antioxidant defenses and biochemical parameters in neotropical fish pacu, Piaractus mesopotamicus (Holmberg, 1887)

Abstract

Copper sulfate is widely used in aquaculture. Exposure to this compound can be harmful to fish, resulting in oxidative metabolism alterations and gill tissue damage. Pacu, Piaractus mesopotamicus, (wt = 43.4 +/- 3.35 g) were distributed in experimental tanks (n = 10; 180 l) and exposed for 48 h to control (without copper addition), 0.4Cu (0.4 mg l(-1)), 0CupH (without copper addition, pH = 5.0) and 0.4CupH (0.4 mg l(-1), pH = 5.0). In liver and red muscle, the superoxide dismutase (SOD) was responsive to the increases in the aquatic copper. The plasmatic intermediary metabolites and hematological variables in the fish of group 0.4Cu were similar to those of the control group. Conversely, the exposure to 0.4CupH caused an increase in the plasmatic lactate, number of red blood cells (RBC) and hemoglobin (Hb). Plasmatic copper concentration [Cu(p)] increased in group 0.4Cu and 0.4CupH, which is higher in group 0.4CupH, suggests an effect of water pH on the absorbed copper. Exposure to 0.4Cu and 0.4CupH resulted in a reduction in the Na(+)/K(+)-ATPase activity and an increase in metallothionein (MT) in the gills. Exposure to 0CupH caused a decrease in glucose and pyruvate concentrations and an increase in RBC, Hb, and the branchial Na(+)/K(+)-ATPase activity. These responses suggest that the fish triggered mechanisms to revert the blood acidosis, save energy and increase the oxygen uptake. MT was an effective biomarker, responding to copper in different pHs and dissolved oxygen. Combined-factors caused more significant disturbance in the biomarkers than single-factors.

Assessing the Effects of Land Use on Surface Water Quality in the Lower uMfolozi Floodplain System, South Africa

“…The pH of most freshwater systems is predominantly determined by or dependent on atmospheric influences, the mineral content of the surrounding rocks, soils and other landforms. It often ranges from 6 to 8, which is ideal for aquatic life [67,68]. pH values ranging between 6.5 and 8.4 are considered acceptable by the SAWQ guidelines for agricultural use.…”

Copper sulfate affects Nile tilapia (Oreochromis niloticus) cardiomyocytes structure and contractile function

“…Several authors have reported a significant production of ROS by copper exposure (Farmen et al 2010;Manzl et al 2004;Nawaz et al 2004;Pourahmad and O'Brien 2000a, b;Puig and Thiele 2002;Sampaio et al 2010;Viarengo et al 1996;Vutukuru et al 2006) beyond reductions in the levels of antioxidant enzymes (Vutukuru et al 2006). Oxidative stress may affect mitochondrial ATP production due to changes in mitochondrial membrane potential (Krumschnabel et al 2005;Manzl et al 2004;Pourahmad and O'Brien 2000a, b;Xiang and Shao 2003) and alter mitochondrial permeability, leading to a complete depletion of ATP by copper (Krumschnabel et al 2005;Pourahmad and O'Brien 2000b).…”

Review of Copper and Copper Nanoparticle Toxicity in Fish

“…Similarly, metallothionine was established to be an effective biomarker in response to copper at different pH and dissolved O 2 levels. These factors work together more effectively to produce significant disturbances in biomarkers rather than individually [ 135 ]. In the next study, juvenile Salmo gairdneri fish were exposed to 25–400 µg Cu/L for 24 h in a standardized environments of varying water hardness, with alkalinity maintained at a constant Na concentration.…”