Sublethal Effects Of Copper Research Articles

Sub Lethal Effects of Copper and Arsenic on Some Biochemical and Hematological Parameters of the Blood in an Air Breathing Fish Heteropneustes fossilis

Study was undertaken to evaluate biochemical and hematological alterations resulting from the exposure of Heteropneustes fossilis to both sub-lethal concentration of copper (1.84 ppm and 1.10ppm) and arsenic (1.10 ppm and 0.78ppm) on various tissues for 15 days, 30 days and 60 days. Three groups of 14 fish were taken as control group, arsenic exposed group and copper exposed group. At the end of experiment periodically blood sample were taken from the control and experimental group of fish. Blood was assayed for selected biochemical and hematological parameters (hematocrit, haemoglobin per cent red blood cell counts, white blood cell counts, MCV, MCH, MCHC, clotting time, plasma protein, plasma glucose, blood plasma GOT, GPT, alkaline phosphatase, cholesterol, triglycerides). The hematological indices of both sub-lethal concentration of both test metal indicated a dose-dependent decrease in hemoglobin values, hematocrit values, red blood counts, MCH, MCHC, which are indication of anemia of the normal chronic type. Clotting time significantly increased in copper exposed fish. A dose-duration dependent increase was observed in MCV and WBC count. Biochemical analysis demonstrated the blood plasma level of protein and glucose was lowered in the exposed fish as compared to the control group, but a significant dose dependent elevation was recorded in all other bio chemical parameters. During exposure time a relative decrease in blood glucose level and an increase in blood serum cholesterol level and SGOT, SGPT, alkaline phosphatase, triglycerides level was increased. The result of present study demonstrates the toxic effect of both test metal in test fish Heteropneustes fossilis and recorded hematological and biochemical parameters can be used as an indicator of copper and arsenic related toxicological stress in fish on been exposed to sublethal concentration of both metal.

Sublethal effects of copper on some biological traits of the amphipod Gammarus aequicauda reared under laboratory conditions

The common and widespread copper contamination in marine coastal environments make toxicity data necessary to assess the aquatic hazard and risk of this metal.In the present study, the sublethal effects of copper on survival, growth and reproduction of Gammarus aequicauda were investigated. Amphipods were exposed for 77d to 2 nominal copper concentrations (50, 100μgL−1).Survival was the most sensitive measure of effect and was significantly reduced, especially during early life stage (juveniles). Growth of amphipods was also negatively affected by copper and the growth impairment in G. aequicauda increases with increasing metal concentration. The reproductive traits were impaired by each of the copper concentrations, even if there were not any significant differences between control and copper treatments. The size at maturity increased with increasing copper, so the smallest ovigerous females in the control and copper treatments were 0.83mm and 1.35mm head length, respectively. There was a positive correlation between the brood size and the body size of the female in all treatments, whilst the fecundity (n°juveniles/female) decreased in the order control, 50 and 100μgCuL−1.Copper demonstrates chronic toxicity to G. aequicauda at realistic environmental concentrations. The results of this study entail that the understanding of chronic toxicity of a substance, especially on population level effects, is crucial to assess the long-term effect of the substance in the ecosystem.

Sub-lethal effects of copper combined with temperature stress in the marine mussel Mytilus galloprovincialis

Sub-lethal effects of copper combined with temperature stress in the marine mussel Mytilus galloprovincialis

Lethal and sub-lethal effects of copper to the african catfish (<i>clarias gariepinus</i>) juveniles

Lethal and sub-lethal effects of copper on Clarias gariepinus were studied using a 96-hour static bioassay. Copper (as copper chloride, CuCl2 . H2O) was used to prepare the stock solution from which five standard concentrations 0.0, 1.8, 3.2, 5.6, and 10.0 mg/L were prepared (coded A – E). 15 juvenile C. gariepinus fish having a mean weight and length 5.8g and 18 cm respectively were used. The 96-hour LC50 estimated using the logarithm method were 0.6, 0.71 and 0.7 mg/l for replicates 1, 2 and 3 respectively with mean as 0.67mg/l. Haematological changes were generally not significant (P> 0.05). Copper concentrations in bone and muscle-tissues were also determined. The mean copper concentration in bone ranged from 1.86 (treatment A) to 17.04 ppm (Treatment E) and muscle 1.29 (treatment A) to 55.5 ppm (treatment E). There were significant differences (p<0.05) in mortality among treatments.

The influence of salinity on copper accumulation and its toxic effects in estuarine animals with differing osmoregulatory strategies

Copper is an important ionoregulatory toxicant in freshwater, but its effects in marine and brackish water systems are less well characterised. The effect of salinity on short-term copper accumulation and sublethal toxicity in two estuarine animals was investigated. The osmoregulating crab Hemigrapsus crenulatus accumulated copper in a concentration-dependent, but salinity-independent manner. Branchial copper accumulation correlated positively with branchial sodium accumulation. Sublethal effects of copper were most prevalent in 125% seawater, with a significant increase in haemolymph chloride noted after 96 h at exposure levels of 510 μg Cu(II) L −1. The osmoconforming gastropod, Scutus breviculus, was highly sensitive to copper exposure, a characteristic recognised previously in related species. Toxicity, as determined by a behavioural index, was present at all salinities and was positively correlated with branchial copper accumulation. At 100% seawater, increased branchial sodium accumulation, decreased haemolymph chloride and decreased haemolymph osmolarity were observed after 48 h exposure to 221 μg Cu(II) L −1, suggesting a mechanism of toxicity related to ionoregulation. However, these effects were likely secondary to a general effect on gill barrier function, and possibly mediated by mucus secretion. Significant impacts of copper on haemocyanin were also noted in both animals, highlighting a potentially novel mechanism of copper toxicity to animals utilising this respiratory pigment. Overall these findings indicate that physiology, as opposed to water chemistry, exerts the greatest influence over copper toxicity. An understanding of the physiological limits of marine and estuarine organisms may be critical for calibration of predictive models of metal toxicity in waters of high and fluctuating salinities.

Sublethal effects of copper on coho salmon: impacts on nonoverlapping receptor pathways in the peripheral olfactory nervous system.

The sublethal effects of copper on the sensory physiology of juvenile coho salmon (Oncorhynchus kisutch) were evaluated. In vivo field potential recordings from the olfactory epithelium (electro-olfactograms) were used to measure the impacts of copper on the responses of olfactory receptor neurons to natural odorants (L-serine and taurocholic acid) and an odorant mixture (L-arginine, L-aspartic acid, L-leucine, and L-serine) over a range of stimulus concentrations. Increases in copper impaired the neurophysiological response to all odorants within 10 min of exposure. The inhibitory effects of copper (1.0-20.0 micrograms/L) were dose-dependent and they were not influenced by water hardness. Toxicity thresholds for the different receptor pathways were determined by using the benchmark dose method and found to be similar (a 2.3-3.0 micrograms/L increase in total dissolved copper over background). Collectively, examination of these data indicates that copper is broadly toxic to the salmon olfactory nervous system. Consequently, short-term influxes of copper to surface waters may interfere with olfactory-mediated behaviors that are critical for the survival and migratory success of wild salmonids.

Sublethal effects of copper on the freshwater crab Potamonautes warreni

The mass specific rates of oxygen consumption ( M ̇ O 2 M b −1), ammonia excretion ( M ̇ NH 4–N M b −1) and carbon dioxide production ( M ̇ CO 2 M b −1) were measured after 7, 14 and 21 days exposure of adult Potamonautes warreni to a sublethal concentration of 1.0 mgCu l −1 (15.75 μmol l −1). Under control (non-copper-exposed) conditions M ̇ O 2 M b −1 was 35.7±8.5 μmol kg −1 min −1 (mean±S.D.), M ̇ NH 4–N M b −1 2.92±0.26 μmol kg −1 min −1 and M ̇ CO 2 M b −1 25.6±9.0 μmol kg −1 min −1. The oxygen:nitrogen (O:N) ratio and respiratory quotient (RQ) were 24.5±3.0 and 0.80±0.06, respectively. M ̇ O 2 M b −1 of copper-exposed crabs showed a significant increase after 7 and 14 days, but decreased significantly by 40% after 21 days. From the increased O:N ratio and RQ below 0.7, it is clear that crabs exposed to 1 mgCu l −1 metabolize lipids during the entire 21-day exposure period. Free fatty acids in the midgut gland were determined by GC-MS, and showed increases of up to 600% in some C14 to C18 fatty acids. It is proposed that the excess lipids inhibit the pyruvate dehydrogenase complex, leading to the acceleration of the gluco- and glyco-neogenic pathways. Increased glyconeogenesis results in elevated glycogen concentrations in all tissues after 21 days. Experiments on acutely exposed P. warreni show increased incorporation of 14C-labelled lactate into glycogen.

The sublethal effects of copper and lead on the haematology and acid-base balance of the groovy mullet, Liza dumerili

Toxicity bioassays were conducted on groovy mullet, Liza dumerili, using copper and lead, in order to assess how these metals affected their blood haematology and acid-base balance. Short-term (96 hours) exposure to lead caused significantly more haematological response [PCO2] than copper, when compared to the control. When copper and lead were applied in combination there were significant increases in bicarbonate content and red blood cell count of the fish. Long-term (28 days) exposure to copper and lead resulted in significant increases in blood glucose, haemoglobin content and the acid-base status of the fish. The results of this study highlight the stress to which estuarine fish are exposed through the uncontrolled discharge of heavy metals and the inherent dangers posed by combinations of metals in the aquatic environment. They will also help emphasise the need to control pollution in order to protect aquatic biodiversity.

Foodborne uptake and sublethal effects of copper and zinc to freshwater snails

Snail habitat selection was strongly influenced in thisresearch by measured copper (Cu) contribution from a powerplant discharge. Laboratory feeding studies showed that thesnail Leptoxis praerosa significantly bioconcentrated Cuwhen fed aufwuchs containing 564 (±269) µg Cu g-1but did not have significant cellulolytic enzyme activityimpairment. No foodborne zinc (Zn) bioconcentration was foundfrom aufwuchs containing up to 20 000 (±18 400) µg Zn g-1. These results suggest that water column Cuconcentrations leading to impairment via feeding mechanismscan be an order of magnitude higher than concentrations causingimpairments via waterborne exposures. Therefore, foodborneuptake might be expected to contribute to toxicity rather thandominate toxicity in most conditions where waterborneconcentrations of metals occur. Changes in food qualityappeared to have a greater overall effect on snail populationsthan foodborne uptake of metals alone. Snail populations took2 years to recover following intensive metal treatment on theplant discharge and subsequent reduction of measured metalconcentrations in both water and aufwuchs.

Sublethal toxic effects of copper on growth, reproduction and litter breakdown activity in the earthworm Lumbricus rubellus, with observations on the influence of temperature and soil pH

The sublethal effects of copper on Lumbricus rubellus Hoffm. have been investigated with respect to growth, cocoon production and litter breakdown activity. The concentrations of Cu in the soil ranged from 13 to 370 mg kg −1. Copper additions to soil caused the greatest decreasing effect on cocoon production. Significant decreases in cocoon production at 2 to 6 weeks (15°C) were found at concentrations in the range of 100 to 150 mg Cu kg −1, applied either to a sandy soil or to a sandy loam. L itter breakdown activity responded less sensitively with significant decreases occuring at 150 to 300 mg Cu kg −1. Body weight was least affected; significant reduction of body weight gain occurred at concentrations greater than 300 mg Cu kg −1, together with the first occurrence of mortality. The copper toxicity observed in the acid sandy soil decreased as the soil pH was adjusted from 4·8 to 7·1. Cocoon production increased and body growth decreased as the temperature increased from 12 to 18°C. Litter breakdown activity at 6 weeks showed an optimum at 15°C. The temperature response remained largely unaltered in Cu-amended soil. The relative effect of copper was generally greater as the temperature decreased. These studies show that copper may seriously affect earthworm populations. They also demonstrate the potential usefulness of L. rubellus as a test species in ecotoxicological evaluation of environmental pollutants in soil.