Histological and morphological alterations induced by copper exposure in Laeonereis acuta (Polychaeta, Nereididae)

Laeonereis acuta (Polychaeta, Nereididae) was collected in an unpolluted (UP) and an polluted (P) site at the Patos Lagoon estuary (Southern Brazil) and maintained under control conditions (UPC and PC, respectively) or exposed to waterborne copper (UPCu and PCu; 500 μg Cu/l), for 48 h. Four groups (aaUPC, aaPC, aaUPCu, and aaPCu) were also pre-exposed for 48 h to ascorbic acid (aa; 0.1 mM) before copper exposure. Histological and morphological alterations, as well as oxygen consumption changes were evaluated. Independently of the sampling site and the pre-exposure to the ascorbic acid, morphological abnormalities were evident in more than 80% of worms exposed to copper. Conspicuous histological changes (coeloma obliteration, cuticle separation from the epidermis, and absence of dorsal vessel) were also observed. In addition, PCu worms showed loss of the digestive epithelium and coiling behavior. Similar oxygen consumption values were observed in control and copper exposed worms.     

Oxidative stress responses in two populations of Laeonereis acuta (Polychaeta, Nereididae) after acute and chronic exposure to copper

Acute (4 days) and chronic (14 days) effects of copper were evaluated on the antioxidant defenses of Laeonereis acuta (Polychaeta) collected in unpolluted (UP) and polluted (P) sites. In the acute assay (125 and 250 micro g Cu/l) superoxide dismutase (SOD) and glutathione S-transferase (GST) activities did not change, whereas catalase (CAT) increased in worms from both the sites. Lipid peroxidation was higher in copper exposed worms from the P site. In the chronic assay (62.5 micro g Cu/l) polychaetes from the P site showed enhanced activities of SOD, GST and CAT and higher contents of metallothionein-like proteins and sulfhydrils compared to worms from UP. Differences in responses between polychaetes from UP and P sites suggest that organisms from the polluted site, P, are more susceptible to oxidative stress conditions.     

Quantitation of metallothionein mRNA from the New Zealand common bully (Gobiomorphus cotidianus) and its implications for biomonitoring

Metallothionein (MT) is a protein found in most eukaryotes where its primary role is the regulation of homeostasis of the essential metals copper and zinc. MTs have an additional protective role through their binding of toxic metals such as cadmium and mercury. Increased expression of MT in response to harmful levels of these metals has been demonstrated for several aquatic species. In this study, the expression of MT in the liver tissue of the New Zealand common bully Gobiomorphus cotidianus was measured by quantifying MT mRNA. A statistically significant increase in MT expression was observed in fish exposed to copper for 48 h, but not those exposed to zinc. Field sampling of common bullies showed a wide variation in individual hepatic MT mRNA levels which did not correlate with fish age, sex, or sampling location. A comparison of two populations of common bullies from a polluted and a control site showed a two‐fold higher mean MT mRNA level in fish from the polluted site. Implications for using MT expression in the common bully as a bio‐monitoring tool are discussed.     

余氯对大亚湾海区平鲷和黑鲷幼鱼的毒性研究

用含游离余氯、化合余氯的海水分别对大亚湾平鲷Rhabdosargussarba、黑鲷Sparusmacrocephalus浸毒处理30min和60min。结果表明,两种形态余氛对色的耗氧率有明显抑制作用,游离余氯对平鲷、黑鲷的48hLC50分别为0．19和0．18mg·L－1,48hLC1分别为0．07和0.06mg·L－1;化合余氯的48hLC50分别为0.56和0．60mg·L－1,48hLC1分别为0．21和0．24mg·L-1。游离余氯的毒性大约是化合余筑的6倍。游离余氯、化合余氯安全阈限估算值分别为0．09和0．28mg·L－1,稍高于48hLC1。     

Effect of copper on the scope for growth of clams (Tapes philippinarum) from a farming area in the Northern Adriatic Sea

Copper is currently the most common biocide in antifouling paints. Levels of this metal were measured in the water, particulate matter and sediments from a shellfish farming area in the Sacca di Goro (Northern Adriatic Sea) over one year. With respect to the 1980s, copper environmental level increased twofold. The release of copper from shellfish farmers' boats was also estimated to be > 250 kg Cu y(-1). Clams Tapes philippinarum were collected in the same area and seasonally exposed to a sublethal (10 microg Cu l(-1)) concentration of copper. Physiological traits were significantly affected by copper exposure (scope for growth declined as a result of reduced clearance rate, increased oxygen consumption and a generally lower absorption efficiency). The results of this study are cause for concern for shellfish farming activities at least in Northern Adriatic, where shellfish farming is a monoculture of T. philippinarum. A strict interpretation of the precautionary principle might suggest that more rigorous regulatory action to control copper inputs in the field would be justified.     

A simple new bioassay based on echinochrome synthesis by larval sea urchins

A simple, rapid and quantitative embryo-larval bioassay that uses changes in echinochrome pigment synthesis as an indicator of seawater toxicity has been developed to allow increased use of sensitive sea urchin bioassays where time, resources and technical expertise may be limited. Several 48 h embryo-larval tests were conducted with lowered salinity and increased concentrations of copper as the potential toxicants. At 48 h the larvae were examined for echinochrome pigment level (E), the number of embryos that had gastrulated (G) and the percentage of gastrulas that had developed to prisms (P). Relationships between the pigment levels (E) and morphological parameters (G and P) were investigated using simple and partial correlation analysis. Reductions in echinochrome levels were correlated with both G and P, and partial correlation analysis showed that changes in echinochrome levels are associated with G, P, or G and P, depending on the experimental conditions. The echinochrome measurement procedure appears to be as good as or better than the morphological examination technique since it is as sensitive, less variable and takes about 25% of the time required for morphological examination.     

Sublethal effects of oiled sediment on the sand worm, Nereis (neanthes) virens: Induced changes in burrowing and emergence

The burrowing and emergence behavior of sand worms, Nereis (Neanthes) virens Sars, in sediment contaminated with sublethal concentrations of Prudhoe Bay crude oil ranging from 74 to 5222 ppm, was studied in the laboratory. Initial burrowing in oiled sediment did not differ from that observed in unoiled sediment. Emergence of exposed worms was related to the oil concentration and the extent of weathering of oiled sediment. Sand worms buried in unoiled sediment did not emerge. Worms dug from oiled sediment after 12 hours' exposure and placed on unoiled sediment were impaired, resulting in a significant increase in time to burrow. However, after 12h, they recovered and burrowed at normal rates. Worms held in oiled sediment for 96 h also recovered. Possible causes for recovery are discussed. Results suggest that oil-induced aberrations may increase vulnerability to predation.     

麻醉剂丁香酚对黄腊鯵耗氧的影响

用不同浓度的丁香酚对体质量为 115～ 175 g的黄腊鲹( Trachinotus blochii)麻醉处理 15 min,每 1分钟测定容器内的氧饱和度 1次.实验结果表明,黄腊鲹的耗氧率明显地受到丁香酚的影响,在各处理组中以 10× 10- 6浓度组的耗氧率为最低( 0.33 mg/(g@ h)), 5× 10- 6浓度组次之( 0.42 mg/(g@ h)),而对照组则较高( 0.57 mg/(g@ h)).同时实验还表明经丁香酚麻醉处理的黄腊鲹鳃活动频率显著地比对照组低.此结果表明了在施用麻醉剂以后,鱼体的活动及对氧气的消耗有明显的下降,丁香酚可以作为活鱼运输过程中有效的麻醉剂.     

Oxidative stress in Laeonereis acuta (Polychaeta, Nereididae): environmental and seasonal effects

Laeonereis acuta was seasonally collected in an industrially polluted site (P) and in an unpolluted site (UP) at the Patos Lagoon estuary (southern Brazil). Glutathione S-transferase (GST), superoxide dismutase (SOD) and catalase (CAT) activity (U/mg protein) was determined in five groups of worms from each site. Metallothionein (MT - mol GSH/g ww) and lipid peroxides content (LPO - nmoles of cumene hydroperoxide/g ww) were also measured. Annual mean values for CAT (UP=3.7+/-0.3; P=5.7+/-0.6), GST (UP=0.034+/-0.003; P=0.045+/-0.004) and MT (UP=0.15+/-0.02; P=0.23+/-0.03) were higher (p<0.05) in worms from the P site. In autumn, CAT activity was higher (p<0.05) in worms from the P site (7.6 +/- 1.3) than in those from the UP site (3.6 +/- 0.4). In summer, MT concentration was higher in worms from the P site (0.37 +/- 0.03) than in those from the UP site (0.19 +/- 0.01). No significant difference (p>0.05) in the LPO content was observed in worms from the different sites or collected in different seasons. These results indicate that worms from the polluted site showed higher antioxidant responses than those from the unpolluted site, sufficient to prevent oxidative damage in terms of LPO.     

Toxicological effects induced by the nanomaterials fullerene and nanosilver in the polychaeta Laeonereis acuta (Nereididae) and in the bacteria communities living at their surface

Fullerene (nC₆₀) and nanosilver (nAg) are nanomaterials with bactericide properties. The increments in their use raise questions about their potential environmental impacts, including estuarine ones. The polychaete Laeonereis acuta (Nereididae) secretes mucus that is colonized by bacteria communities. We analyzed the antioxidant and oxidative damage responses of anterior, middle and posterior region of L. acuta and bacteria communities after nC₆₀ or nAg exposure during 24 h. Molecular analysis showed a prevalence of Vibrio genera in the communities. Bacteria biomass was lowered in worms exposed to 1.0 mg/L of nAg. nC₆₀ reduced total antioxidant capacity of bacteria from worms exposed to 0.1 mg/L. Worms anterior region presented lower antioxidant capacity after exposure to 1.0 mg nC₆₀/L, and the same was observed in the posterior region of worms exposed to 1.0 mg nAg/L. Lipid peroxidation was reduced in the anterior region of worms exposed to nC₆₀ and the opposite was observed in the posterior region.     

Tolerance, accumulation and depuration in an intertidal gastropod, Turbo intercostalis, exposed to cadmium

Laboratory experiments were carried out to study cadmium (Cd) toxicity in an intertidal gastropod, Turbo intercostalis. Tolerance studies revealed an LC₅₀ of 6.18 ppm for 96 h. Experiments were also conducted to determine oxygen consumption and bioaccumulation of the metal by exposing the snails to a sublethal concentration of Cd (1.24 ppm) for 20 days. A significant fall in oxygen consumption was observed from 48 h onwards with maximum decrease (65.5%) at 20 days. The accumulation of Cd was determined in gonad-digestive gland (GDG) complex, mantle and foot at different intervals. There was a gradual increase in accumulation with exposure time in all tissues. The accumulation of Cd was: GDG complex>mantle>foot. The percentage body burden of the metal showed a decreasing trend in the mantle and an increasing trend in GDG complex. The fractional retention coefficients increased with exposure time. The snails exhibited a tissue-specific depuration of the metal and the trend was similar to that of accumulation. The results suggest that T. intercostalis may be a useful species for biomonitoring studies.     

Effects of the multiple stressors copper and reduced salinity on the metabolism of the hermatypic coral Porites lutea

This study investigates the physiological responses in the hermatypic coral Porites lutea when exposed to a combination of reduced salinity (from ambient 30 psu to 20 psu) and two concentrations of copper (CuS04), 10 microg 1(-1) and 30 microg 1(-1). Corals were exposed for 14 h and changes in metabolism in terms of primary production rate per chlorophyll a and respiration per surface area (cm2) were used as measures of stress. The results showed no significant changes in respiration rate in any of the treatments compared with controls, or between treatments. The primary production rate, however, displayed a more complex pattern. Corals exposed to reduced salinity, 30 microg 1(-1) copper, and the combination of the two stressors significantly reduced the production rate, whereas corals exposed to 10 microg 1(-1) only, remained unaffected. However, adding 10 microg 1(-1) copper to reduced salinity did not affect the production rate thus indicating an antagonistic effect.     

Different cardiac response to copper in limpets from metal polluted and clean shores of Hong Kong

The gastropod limpet, Cellana grata, is common on moderately exposed to exposed Hong Kong rocky shores. On the basis of the existing literature on trace metal contamination in Hong Kong, four sites were identified, representative of highly polluted (Aberdeen and Lei Yue Mun) and clean (Cape d'Aguilar and Clear Water Bay) conditions. Limpets from the two polluted sites showed similar, but significantly higher body concentrations of copper than limpets from the two clean sites, which were also similar. Non-invasive measurements of cardiac activity of limpets from the four sites showed between site differences in baseline heart rates under standard seawater, irrespective of pollution level. When acutely exposed to water borne copper (2 h, 0.5+/-0.06 SD ppm), however, limpets from clean sites showed a significantly higher increase in inter-beating time (bradycardia) than those from polluted sites. These results highlight the potential use of cardiac activity to assess the exposure of natural populations of limpets to trace metal pollution.     

Copper complexation by fulvic acid affects copper toxicity to the larvae of the polychaete Hydroides elegans

Copper toxicity is influenced by a variety of environmental factors including dissolved organic matter (DOM). We examined the complexation of copper by fulvic acid (FA), one of the major components of DOM, by measuring the decline in labile copper by anodic stripping voltammetrically (ASV). The data were described using a one-site ligand binding model, with a ligand concentration of 0.19micromol site mg(-1) C, and a logK' of 6.2. The model was used to predict labile copper concentration in a bioassay designed to quantify the extent to which Cu-FA complexation affected copper toxicity to the larvae of marine polychaete Hydroides elegans. The toxicity data, when expressed as labile copper concentration causing abnormal development, were independent of FA concentration and could be modeled as a logistic function, with a 48-h EC(50) of 58.9microgl(-1). However, when the data were expressed as a function of total copper concentration, the toxicity was dependent on FA concentration, with a 48-h EC(50) ranging from 55.6microgl(-1) in the no-FA control to 137.4microgl(-1) in the 20mgl(-1) FA treatment. Thus, FA was protective against copper toxicity to the larvae, and such an effect was caused by the reduction in labile copper due to Cu-FA complexation. Our results demonstrate the potential of ASV as a useful tool for predicting metal toxicity to the larvae in coastal environment where DOM plays an important role in complexing metal ions.     

Oxidative stress in Laeonereis acuta (Polychaeta, Nereididae): environmental and seasonal effects

Laeonereis acuta was seasonally collected in an industrially polluted site (P) and in an unpolluted site (UP) at the Patos Lagoon estuary (southern Brazil). Glutathione S-transferase (GST), superoxide dismutase (SOD) and catalase (CAT) activity (U/mg protein) was determined in five groups of worms from each site. Metallothionein (MT – μmol GSH/g ww) and lipid peroxides content (LPO – nmoles of cumene hydroperoxide/g ww) were also measured. Annual mean values for CAT (UP=3.7±0.3; P=5.7±0.6), GST (UP=0.034±0.003; P=0.045±0.004) and MT (UP=0.15±0.02; P=0.23±0.03) were higher (p<0.05) in worms from the P site. In autumn, CAT activity was higher (p<0.05) in worms from the P site (7.6 ± 1.3) than in those from the UP site (3.6 ± 0.4). In summer, MT concentration was higher in worms from the P site (0.37 ± 0.03) than in those from the UP site (0.19 ± 0.01). No significant difference (p>0.05) in the LPO content was observed in worms from the different sites or collected in different seasons. These results indicate that worms from the polluted site showed higher antioxidant responses than those from the unpolluted site, sufficient to prevent oxidative damage in terms of LPO.     

Rates of oxygen consumption and tolerance of hypoxia and desiccation in Chinese black sleeper(Bostrichthys sinensis) and mudskipper(Boleophthalmus pectinirostris) embryos

1Introduction Afossorialmodeoflifehasbeenadoptedbynu merousfishes(Gibson,1982).Burrowingmodeof lifeclearlyoffersanumberofadvantages,butburro wingfishmustalsobeadaptedtocopewiththespe cialproblemsthatthislifestylepresents.Fishthat constructburrowsininterti…     

重金属对日本对虾仔虾存活及代谢酶活力的影响

本研究测定了铜、锌、镉对不同盐度下日本对虾仔虾的24hLC50、48hLC50、96hLC50,三种金属毒性大小依次为Cd2＋＞Cu2＋＞Zn2＋。对次致死浓度下仔虾的碱性磷酸酶（AKP）、酸性磷酸酶（ACP）、谷丙转氨酶（GPT）、及谷草转氨酶（GOT）的活性的测定结果表明：重金属对AKP、GPT、GOT活性有不同程度的抑制作用;且随着浓度的增高,抑制作用越明显。但对ACP活性有激活作用,且随着浓度的增高,激活作用越明显。     

Spatio-temporal Changes of Sabellarian Reefs Built by the Sedentary Polychaete Sabellaria alveolata (Linné)

Abstract. Important intertidal sabellarian reefs are built by the polychaete Sabellaria alveolata (L^INNÉ) in the Mont Saint-Michel Bay in Normandy at Champeaux (France). Typical profiles and plans were done over a ten year period. At the same time, population dynamics were examined during the last six years. At this site a nearly complete morphological cycle spread itself over more than ten years. Initially built on rock substrate (primary settlement phase), the studied reefs actually lie on a sandy shore. The growth phase begins by stages of balls which are then joined with new settlements between or on older tubes (secondary settlement). This phase comes to an end with an important platform stage. Then, the destruction phase brings us back to dead eroded reefs on which new worms can settle (secondary settlement). This cycle seems to be independent of the age of the living population, although new settlements of young worms and also sufficient hydrodynamics seem necessary.     

Effects of long-term exposure to silver or copper on growth, bioaccumulation and histopathology in the blue mussel Mytilus edulis

The purpose of this study was to determine the long-term accumulation of either silver or copper from low concentrations in seawater by blue mussels, Mytilus edulis. Mussels raised from eggs in the laboratory to the age of 2·5 months (approximately 4·5 mm in length) were continuously exposed to 0, 1, 5 and 10μg/liter of either silver (nitrate) or copper (chloride) and sampled at 12, 18 and 21 months for growth studies, measurements of metal accumulation and histopathological examination.Whole-body soft tissues were analyzed for the presence of both silver and copper, as background levels of copper in the incoming seawater averaged 2–4 μg/liter. Mussels exposed to silver had accumulated significant amounts of silver only at the highest test concentration (10 μg/liter Ag) after 12 months, but at 18 and 21 months significant levels were accumulated at all three test concentrations. Mussels exposed to copper accumulated significant amounts of copper at 5 and 10 μg/liter Cu after all three sampling periods, but not at 1μg/liter. Silver-exposed animals also accumulated significantly greater amounts of copper than control animals.In a comparative study, field-collected juvenile mussels (approximately 16·1 mm in shell length) and adult mussels (approximately 53·4 mm in shell length) were exposed for 12 months to 0, 5, 25 and 50 μg/liter silver only and subsequently sampled for metal-accumulation analyses and growth measurements. Juvenile mussels accumulated significant amounts of silver at all test concentrations, with the exception of mussels exposed to 5 μg/liter Ag for 6 months. Copper accumulation in the silver-exposed juveniles was significant only at 50 μg/liter Ag after 6 months, but at all test concentrations after 12 months. Adult mussels exposed to silver accumulated significant levels of both silver and copper, but at somewhat lower levels than juveniles.In the growth study, silver had no effect on laboratory reared mussels at the highest concentration of 10 μg/liter tested, whereas copper at 10 μg/liter did appear to affect growth as early as 4 months after the start of experimental exposure. Field-collected juvenile mussels did show inhibition in growth after 6 months' exposure to 25 and 50 μg/liter Ag, with some growth occurring after 12 months. Adults also showed inhibition in growth after 6 months but not at 12 months.Histopathological examination of mussels exposed to either 5 or 10 μg/liter of copper for 18 months showed changes in the digestive diverticula, gastrointestinal tract, reproductive tract and muscle tissues. These changes were more noticeable in mussels exposed to 5 μg/liter Cu than in those exposed to 10 μg/liter. Mussels exposed to silver for 21 months showed yellowish to black particulate deposition in the basement membrane and connective tissue of the various organs and tissues. Silver deposition increased with increasing test concentration.     

Protein expression signatures and lysosomal stability in Mytilus edulis exposed to graded copper concentrations.

Protein expression and lysosomal stability were observed in Mytilus edulis exposed to 0, 20, 40, 60, and 80 ppb copper sulfate for 24 h in a static exposure system. Haemolymph was removed from each mussel and analyzed for lysosomal damage using the Neutral Red retention assay expressed as the ratio of lysosomal size to cell area, the lysosomal destabilization ratio. Gill tissue from the same individuals was dissected, homogenized and the proteins extracted and then separated using two-dimensional gel electrophoresis. Two-dimensional protein maps from each concentration were analyzed using MELANIE II 2D gel analysis software (Biorad). Lysosomal damage increased with each dosage, with LDRs ranging from 0.18 +/- 0.01 at 0 ppb copper sulfate to 0.32 +/- 0.11 at 80 ppb copper sulfate. Orthogonal comparisons showed that the control, 20 and 40 ppb classes together differed significantly (P < 0.05) from the 60 and 80 ppb classes together. Specific protein expression signatures were identified at each dosage.