We report here arsenic speciation in 1643 freshwater fish samples,representing 14 common fish species from 53 waterbodies in Alberta,Canada.Arsenic species were extracted from fish muscle tissue.Arsenic species in the...We report here arsenic speciation in 1643 freshwater fish samples,representing 14 common fish species from 53 waterbodies in Alberta,Canada.Arsenic species were extracted from fish muscle tissue.Arsenic species in the extracts were separated using anion-exchange high-performance liquid chromatography(HPLC)and quantified using inductively coupled plasma mass spectrometry(ICPMS).The total arsenic concentrations in fish ranged from 2.8 to 1200μg/kg(in wet weight of sample)(mean 71±101μg/kg),which are all below the 2000μg/kg(wet weight)maximum allowable total arsenic in fish,recommended by the Ontario Ministry of the Environment.In 99.7%,or 1638 of all 1643 freshwater fish samples analyzed,arsenobetaine(AsB)was detectable,with concentrations higher than the method detection limit of 0.25μg/kg(wet weight).Dimethylarsinic acid(DMA)was detectable(concentration>0.25μg/kg)in 92.1%,or 1514 of the 1643 freshwater fish samples.Inorganic arsenate(iAs^(Ⅴ))was detectable(>0.25μg/kg)in 1119 fish(i.e.,68.1% of 1643 samples).Monomethylarsonic acid(MMA)was detectable(>0.25μg/kg)in 418 fish(25.4%of 1643 samples).The concentrations of arsenic species in the 1643 fish samples varied by as much as three orders of magnitude,ranging from below the method detection limit of 0.25μg/kg to the maximum concentrations of 380μg/kg for AsB,150μg/kg for DMA,70μg/kg for iAs^(Ⅴ),and 51μg/kg for MMA.AsB made up 46.1%±26.2% of total arsenic species.Arsenic speciation patterns varied between lake whitefish,northern pike,and walleye,the three most common types of fish analyzed.The relative proportion of DMA in northern pike was larger than in lake whitefish and walleye,and conversely,the relative proportion of iAs^(Ⅴ) was lower in northern pike.Seven unknown arsenic species were detected,and their chromatographic retention time did not match with those of available arsenic standards.At least one unknown arsenic species was detected in 33.4%,or 549 of 1643 freshwater fish samples.The concentrations of unknown arsenic species were as high as 61μg/kg.Future research is necessary to identify unknown arsenic species and to determine contributing factors to the observed arsenic species patterns and concentrations.展开更多
Predation is thought to be one of the main structuring forces in animal communities. However, se- lective predation is often measured on isolated traits in response to a single predatory species, but only rarely are s...Predation is thought to be one of the main structuring forces in animal communities. However, se- lective predation is often measured on isolated traits in response to a single predatory species, but only rarely are selective forces on several traits quantified or even compared between different predators naturally occurring in the same system. In the present study, we therefore measured be- havioral and morphological traits in young-of-the-year Eurasian perch Perca fluviatilis and com- pared their selective values in response to the 2 most common predators, adult perch and pike Esox lucius. Using mixed effects models and model averaging to analyze our data, we quantified and compared the selectivity of the 2 predators on the different morphological and behavioral traits. We found that selection on the behavioral traits was higher than on morphological traits and perch predators preyed overall more selectively than pike predators. Pike tended to positively se- lect shallow bodied and nonvigilant individuals （i.e. individuals not performing predator inspec- tion）. In contrast, perch predators selected mainly for bolder juvenile perch （i.e. individuals spend- ing more time in the open, more active）, which was most important. Our results are to the best of our knowledge the first that analyzed behavioral and morphological adaptations of juvenile perch facing 2 different predation strategies. We found that relative specific predation intensity for the di- vergent traits differed between the predators, providing some additional ideas why juvenile perch display such a high degree of phenotypic plasticity.展开更多
Development perturbations may affect the regular phenotype and are commonly measured through fluctuat-ing asymmetry (FA) levels. Short-term climatic variations, that modify the temperature, can influence chemical and ...Development perturbations may affect the regular phenotype and are commonly measured through fluctuat-ing asymmetry (FA) levels. Short-term climatic variations, that modify the temperature, can influence chemical and physical water characteristics. Fishes have been used as model organisms for studying stress-induced changes in body symmetry, since they are ectothermic, good bioindicators, easy to find and having economic relevance. Northern pike being a holoarctic, big, edible, top predator is one of the most economically important freshwater fish for recreational and commercial fisheries and freshwater ecosystems management. The isolated population of Lake Trasimeno (Central Italy)—in good health conditions and that can be considered one of the genetically best conserved of Italy—, was chosen as model. FA, seven mi-crosatellite loci and early developmental stages were investigated in order to correlate the developmental stability of this population to its genetic variability and to environmental perturbations. The results obtained underlined a positive correlation (>>0.40) between FA indexes and temperature;the non-parametric Kruskall- Wallis test showed significant differences in FA levels for some FA indexes and parameters. Over-all results underlined that FA increased in individuals grown at a temperature above 8°C as compared with those grown at 5°C or at lower temperatures. Both positive and negative correlations between FA parameters and chemical and physical water characteristics were shown. The comparison of genetic and FA data under-lined a low correlation between microsatellite and FA pairwise distances, nevertheless a positive and signifi-cant correlation emerged for some FA measurements and microsatellite data. In particular, only Elu87 locus showed a statistical significant correlation versus total FA. Finally, as expected, results indicated that the in-cubation time was temperature-dependent;the ODT was in the range 8–10°C and lower and higher tempera-tures caused drastic embryo mortality. These results showed robust correlations, both positive and negative, between some FA parameters and chemical and physical characters and were in agreement with the assump-tion that temperature variations as well as pH, conductibility and chloride variation, may increase molecular perturbations and, subsequently, the global developmental noise during development. These data suggest that FA could be considered a measure of animal welfare. The relative breeding easiness of this species may be a valid tool for the estimation of controlled environmental stress influences, not only of thermal origin, and a valid information basis for studies on wild populations. Furthermore, it has long been debated whether FA levels depend upon genetic variability, the particular molecular marker notwithstanding, and whether it is possible to use one or more molecular markers to better understand FA data. The Mantel tests performed in this study showed very interesting correlations between FA and the investigated microsatellites. For the lack of a linkage map for the investigated microsatellite loci, it is presently impossible to establish the relation-ships between the FA parameter and the microsatellite loci that the Mantel test defines as correlated.展开更多
This study was conducted to determine the contamination data of some heavy metals in 10 fish tissue samples of two different fish species---common carp and Northern pike from four different fish ponds and to compare t...This study was conducted to determine the contamination data of some heavy metals in 10 fish tissue samples of two different fish species---common carp and Northern pike from four different fish ponds and to compare the level of contamination and the differences in the concentration of these elements between these two fish species and between compared fish ponds. In various fish ponds, metal concentrations in the carp muscle tissue varied depending on the metal type. Between compared fish ponds, there were significant differences （P 〈 0.01） in the concentration in muscle carp tissue, except for cadmium. Metal concentrations in the pike muscle tissue also varied among fish ponds, depending on the type of metal. In all compared cases, there were significant differences between metal concentration in pike muscle tissue （P 〈 0.01）. Lead and cadmium concentration in pike muscle tissue were significantly higher （P 〈 0.01, P 〈 0.05, respectively）, and mercury and arsenic concentration were significantly lower （P 〈 0.01） than concentration of this heavy metals in carp muscle tissue in all comapered fish ponds. The results obtained in this study indicate variation in a range of examined metal concentration in muscle tissue, which seems to be typical for the Serbian fish ponds, but is lower than those in rivers with considerable anthropogenic impact.展开更多
According to the latest report of Pike Research,the demand for rare earth in the new energy technology field will break the mark of 12,000 tons to reach 12,920 tons in 2017 from about 9,000 tons in 2011,indicating rap...According to the latest report of Pike Research,the demand for rare earth in the new energy technology field will break the mark of 12,000 tons to reach 12,920 tons in 2017 from about 9,000 tons in 2011,indicating rapid development of China’s rare earth hydrogen storage material industry.展开更多
基金supported by Alberta Health,Alberta Innovates,the Canada Research Chairs program,the Canadian Institutes of Health Research,and the Natural Sciences and Engineering Research Council of Canada.
文摘We report here arsenic speciation in 1643 freshwater fish samples,representing 14 common fish species from 53 waterbodies in Alberta,Canada.Arsenic species were extracted from fish muscle tissue.Arsenic species in the extracts were separated using anion-exchange high-performance liquid chromatography(HPLC)and quantified using inductively coupled plasma mass spectrometry(ICPMS).The total arsenic concentrations in fish ranged from 2.8 to 1200μg/kg(in wet weight of sample)(mean 71±101μg/kg),which are all below the 2000μg/kg(wet weight)maximum allowable total arsenic in fish,recommended by the Ontario Ministry of the Environment.In 99.7%,or 1638 of all 1643 freshwater fish samples analyzed,arsenobetaine(AsB)was detectable,with concentrations higher than the method detection limit of 0.25μg/kg(wet weight).Dimethylarsinic acid(DMA)was detectable(concentration>0.25μg/kg)in 92.1%,or 1514 of the 1643 freshwater fish samples.Inorganic arsenate(iAs^(Ⅴ))was detectable(>0.25μg/kg)in 1119 fish(i.e.,68.1% of 1643 samples).Monomethylarsonic acid(MMA)was detectable(>0.25μg/kg)in 418 fish(25.4%of 1643 samples).The concentrations of arsenic species in the 1643 fish samples varied by as much as three orders of magnitude,ranging from below the method detection limit of 0.25μg/kg to the maximum concentrations of 380μg/kg for AsB,150μg/kg for DMA,70μg/kg for iAs^(Ⅴ),and 51μg/kg for MMA.AsB made up 46.1%±26.2% of total arsenic species.Arsenic speciation patterns varied between lake whitefish,northern pike,and walleye,the three most common types of fish analyzed.The relative proportion of DMA in northern pike was larger than in lake whitefish and walleye,and conversely,the relative proportion of iAs^(Ⅴ) was lower in northern pike.Seven unknown arsenic species were detected,and their chromatographic retention time did not match with those of available arsenic standards.At least one unknown arsenic species was detected in 33.4%,or 549 of 1643 freshwater fish samples.The concentrations of unknown arsenic species were as high as 61μg/kg.Future research is necessary to identify unknown arsenic species and to determine contributing factors to the observed arsenic species patterns and concentrations.
文摘Predation is thought to be one of the main structuring forces in animal communities. However, se- lective predation is often measured on isolated traits in response to a single predatory species, but only rarely are selective forces on several traits quantified or even compared between different predators naturally occurring in the same system. In the present study, we therefore measured be- havioral and morphological traits in young-of-the-year Eurasian perch Perca fluviatilis and com- pared their selective values in response to the 2 most common predators, adult perch and pike Esox lucius. Using mixed effects models and model averaging to analyze our data, we quantified and compared the selectivity of the 2 predators on the different morphological and behavioral traits. We found that selection on the behavioral traits was higher than on morphological traits and perch predators preyed overall more selectively than pike predators. Pike tended to positively se- lect shallow bodied and nonvigilant individuals （i.e. individuals not performing predator inspec- tion）. In contrast, perch predators selected mainly for bolder juvenile perch （i.e. individuals spend- ing more time in the open, more active）, which was most important. Our results are to the best of our knowledge the first that analyzed behavioral and morphological adaptations of juvenile perch facing 2 different predation strategies. We found that relative specific predation intensity for the di- vergent traits differed between the predators, providing some additional ideas why juvenile perch display such a high degree of phenotypic plasticity.
文摘Development perturbations may affect the regular phenotype and are commonly measured through fluctuat-ing asymmetry (FA) levels. Short-term climatic variations, that modify the temperature, can influence chemical and physical water characteristics. Fishes have been used as model organisms for studying stress-induced changes in body symmetry, since they are ectothermic, good bioindicators, easy to find and having economic relevance. Northern pike being a holoarctic, big, edible, top predator is one of the most economically important freshwater fish for recreational and commercial fisheries and freshwater ecosystems management. The isolated population of Lake Trasimeno (Central Italy)—in good health conditions and that can be considered one of the genetically best conserved of Italy—, was chosen as model. FA, seven mi-crosatellite loci and early developmental stages were investigated in order to correlate the developmental stability of this population to its genetic variability and to environmental perturbations. The results obtained underlined a positive correlation (>>0.40) between FA indexes and temperature;the non-parametric Kruskall- Wallis test showed significant differences in FA levels for some FA indexes and parameters. Over-all results underlined that FA increased in individuals grown at a temperature above 8°C as compared with those grown at 5°C or at lower temperatures. Both positive and negative correlations between FA parameters and chemical and physical water characteristics were shown. The comparison of genetic and FA data under-lined a low correlation between microsatellite and FA pairwise distances, nevertheless a positive and signifi-cant correlation emerged for some FA measurements and microsatellite data. In particular, only Elu87 locus showed a statistical significant correlation versus total FA. Finally, as expected, results indicated that the in-cubation time was temperature-dependent;the ODT was in the range 8–10°C and lower and higher tempera-tures caused drastic embryo mortality. These results showed robust correlations, both positive and negative, between some FA parameters and chemical and physical characters and were in agreement with the assump-tion that temperature variations as well as pH, conductibility and chloride variation, may increase molecular perturbations and, subsequently, the global developmental noise during development. These data suggest that FA could be considered a measure of animal welfare. The relative breeding easiness of this species may be a valid tool for the estimation of controlled environmental stress influences, not only of thermal origin, and a valid information basis for studies on wild populations. Furthermore, it has long been debated whether FA levels depend upon genetic variability, the particular molecular marker notwithstanding, and whether it is possible to use one or more molecular markers to better understand FA data. The Mantel tests performed in this study showed very interesting correlations between FA and the investigated microsatellites. For the lack of a linkage map for the investigated microsatellite loci, it is presently impossible to establish the relation-ships between the FA parameter and the microsatellite loci that the Mantel test defines as correlated.
文摘This study was conducted to determine the contamination data of some heavy metals in 10 fish tissue samples of two different fish species---common carp and Northern pike from four different fish ponds and to compare the level of contamination and the differences in the concentration of these elements between these two fish species and between compared fish ponds. In various fish ponds, metal concentrations in the carp muscle tissue varied depending on the metal type. Between compared fish ponds, there were significant differences （P 〈 0.01） in the concentration in muscle carp tissue, except for cadmium. Metal concentrations in the pike muscle tissue also varied among fish ponds, depending on the type of metal. In all compared cases, there were significant differences between metal concentration in pike muscle tissue （P 〈 0.01）. Lead and cadmium concentration in pike muscle tissue were significantly higher （P 〈 0.01, P 〈 0.05, respectively）, and mercury and arsenic concentration were significantly lower （P 〈 0.01） than concentration of this heavy metals in carp muscle tissue in all comapered fish ponds. The results obtained in this study indicate variation in a range of examined metal concentration in muscle tissue, which seems to be typical for the Serbian fish ponds, but is lower than those in rivers with considerable anthropogenic impact.
文摘According to the latest report of Pike Research,the demand for rare earth in the new energy technology field will break the mark of 12,000 tons to reach 12,920 tons in 2017 from about 9,000 tons in 2011,indicating rapid development of China’s rare earth hydrogen storage material industry.
