The Experts below are selected from a list of 237 Experts worldwide ranked by ideXlab platform
M A Alikhan - One of the best experts on this subject based on the ideXlab platform.
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cadmium and nickel uptake by tissues of cambarus bartoni astacidae Decapoda Crustacea effects on copper and zinc stores
Water Research, 1993Co-Authors: Simon M Mwangi, M A AlikhanAbstract:Abstract Cadmium and copper contents of the hepatopancreas in adult intermoult Cambarus bartoni , exposed for 72 h to 12.5, 62.5 and 125 μg Cd 1 −1 , were significantly higher than those of the control. Whereas Cd contents were significantly higher in crayfish exposed to 125 μ g Cd 1 −1 , Cu contents were significantly lower in those receiving 62.5 μ g Cd 1 −1 . Antennal glands in Cd-exposed isopods contained approx. 5–8 times higher Cd, and 2–4 times lower Cu than those in the control. Differences in Zn contents of abdominal muscles and gills, Cd contents of abdominal muscles and exoskeleton and Cu contents of abdominal muscles, gonads and exoskeleton of the Cd-exposed crayfish were not significant at the 5% level. Similarly, Ni contents of antennal glands, gonads and hepatopancreas of the crayfish receiving 10–5000 μ g Ni 1 −1 ranged between 18.8 and 25.0, 3.2 and 16.3, and 4.0 and 6.7 μ g g −1 wet wt, respectively. Differences in Ni contents of abdominal muscles and alimentary canal, as well as Cu and Zn contents of the antennal glands, exoskeleton, gills and haemolymph between Ni-exposed and control crayfish were not significant at the 5% level. The study provides evidence of competition between Cd and Cu, and Ni and Cu. However, Zn stores of various tissues remained unaffected by the presence of either Cd or Ni.
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The relationship between copper and nickel levels in the diet, and their uptake and accumulation by Cambarus bartoni (Fabricius) (Decapoda, Crustacea)
Water Research, 1991Co-Authors: M. Bardeggia, M A AlikhanAbstract:Abstract Highest hepatopancreatic Cu concentrations of 588 and 666 μg Cu g −1 wet wt among Cambarus bartoni , fed in the laboratory at 24–26°C for 4 wk on beef-liver enriched with either 500 μg Cu g −1 wet wt, 100 μg Ni g −1 wet wt or a mixture of 500 μg Cu + 200 μg Ni g −1 wet wt, 1000 μg Cu + 100 μg Ni g −1 wet wt or 1000 μg Cu + 200 μg Ni g −1 wet wt, were recorded in animals reared on 100 μg Ni or a mixture of 1000 μg Cu + 100 μg Ni g −1 wet wt, respectively, and the lowest (131 and 136 μg Cu g −1 wet wt) in those on a mixture of 1000 μg Cu + 200 μg Ni g −1 wet wt, or in the control. Highest Ni concentrations of 10.3 and 12.1 μg Ni g −1 wet wt were recorded in animals fed on a mixture of 500 μg Cu + 200 μg Ni or 1000 μg Cu + 200 μg Ni g −1 wet wt, respectively, and lowest (3.2–3.7 μg Ni g −1 wet wt) in those subjected to remaining treatments, including the control. In all treatments, including the control, 20–94% of Cu was contained in the hepatopancreas, 1–11% in the abdominal muscles, 2–25% in the alimentary canal, 2–29% in the gills and 2–32% in the exoskeleton, while 6–37% Ni was present in the hepatopancreas, 2–18% in the abdominal muscles, 12–52% in the alimentary canal, 17–48% in the gills and 11–31% in the exoskeleton. The significance of these findings is discussed.
H H Harvey - One of the best experts on this subject based on the ideXlab platform.
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sublethal copper toxicity and food response in the freshwater crayfish cambarus bartonii cambaridae Decapoda Crustacea
Ecotoxicology and Environmental Safety, 2000Co-Authors: M Sherba, D W Dunham, H H HarveyAbstract:Food response preceding and following exposure to Cu concentrations of 0.00, 0.02, and 0.2 mg/L was observed in male and female Cambarus bartonii from an uncontaminated, freshwater lake. The animals were tested in a Y-maze. Control animals demonstrated food localization, and the treated animals, either no localization or slight food avoidance. The latency for localization in the Cu-exposed males increased. Females revealed slight increases in latency. There were no significant differences between the low and the high Cu concentration groups in food detection or latency. However, there was an increase in mortality in the higher concentration group and significant difference in mortality among three copper concentrations (P<0.02). Females seem to recover from Cu-induced impairment slightly faster than males, suggesting a more efficient mechanism for detoxifying copper. Female mortality, however, remained equally high in the high Cu concentration group. The toxic effects of copper persist after removal of the toxicant and occur at concentrations much lower than reported lethal levels.
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Sublethal Copper Toxicity and Food Response in the Freshwater Crayfish Cambarus bartonii (Cambaridae, Decapoda, Crustacea)
Ecotoxicology and environmental safety, 2000Co-Authors: M Sherba, D W Dunham, H H HarveyAbstract:Food response preceding and following exposure to Cu concentrations of 0.00, 0.02, and 0.2 mg/L was observed in male and female Cambarus bartonii from an uncontaminated, freshwater lake. The animals were tested in a Y-maze. Control animals demonstrated food localization, and the treated animals, either no localization or slight food avoidance. The latency for localization in the Cu-exposed males increased. Females revealed slight increases in latency. There were no significant differences between the low and the high Cu concentration groups in food detection or latency. However, there was an increase in mortality in the higher concentration group and significant difference in mortality among three copper concentrations (P
Poul Bjerregaard - One of the best experts on this subject based on the ideXlab platform.
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The effect of salinity and calcium concentration on the apparent water permeability of Cherax destructor, Astacus astacus and Carcinus maenas (Decapoda, Crustacea)
Comparative Biochemistry and Physiology Part A: Physiology, 1995Co-Authors: Allan Dahl Rasmussen, Poul BjerregaardAbstract:Abstract The effect of calcium concentration and salinity on the apparent water permeability (AWP) has been investigated in three decapods: the Australian Yabbie (Cherax destructor), the noble crayfish (Astacus astacus) and the shore crab (Carcinus maenas). C. destructor does not change its AWP with changing Ca concentration or salinity. The AWP of A. astacus decreases when animals are acclimated to low and high salinities (0.09 and 24 mM NaCl) compared with intermediate ones (0.36, 0.72 and 6 mM NaCl). At high Ca concentrations (5 mM Ca) salinity does not affect AWP. C. maenas decreases its AWP with decreasing salinity. This decrease is most profound when Ca concentration is low. The observed interspecific differences are discussed in terms of habitat, strategy and evolution.
M Sherba - One of the best experts on this subject based on the ideXlab platform.
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sublethal copper toxicity and food response in the freshwater crayfish cambarus bartonii cambaridae Decapoda Crustacea
Ecotoxicology and Environmental Safety, 2000Co-Authors: M Sherba, D W Dunham, H H HarveyAbstract:Food response preceding and following exposure to Cu concentrations of 0.00, 0.02, and 0.2 mg/L was observed in male and female Cambarus bartonii from an uncontaminated, freshwater lake. The animals were tested in a Y-maze. Control animals demonstrated food localization, and the treated animals, either no localization or slight food avoidance. The latency for localization in the Cu-exposed males increased. Females revealed slight increases in latency. There were no significant differences between the low and the high Cu concentration groups in food detection or latency. However, there was an increase in mortality in the higher concentration group and significant difference in mortality among three copper concentrations (P<0.02). Females seem to recover from Cu-induced impairment slightly faster than males, suggesting a more efficient mechanism for detoxifying copper. Female mortality, however, remained equally high in the high Cu concentration group. The toxic effects of copper persist after removal of the toxicant and occur at concentrations much lower than reported lethal levels.
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Sublethal Copper Toxicity and Food Response in the Freshwater Crayfish Cambarus bartonii (Cambaridae, Decapoda, Crustacea)
Ecotoxicology and environmental safety, 2000Co-Authors: M Sherba, D W Dunham, H H HarveyAbstract:Food response preceding and following exposure to Cu concentrations of 0.00, 0.02, and 0.2 mg/L was observed in male and female Cambarus bartonii from an uncontaminated, freshwater lake. The animals were tested in a Y-maze. Control animals demonstrated food localization, and the treated animals, either no localization or slight food avoidance. The latency for localization in the Cu-exposed males increased. Females revealed slight increases in latency. There were no significant differences between the low and the high Cu concentration groups in food detection or latency. However, there was an increase in mortality in the higher concentration group and significant difference in mortality among three copper concentrations (P
A. R. Mcvean - One of the best experts on this subject based on the ideXlab platform.
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Autotomy in Carcinus maenas (Decapoda: Crustacea)
Journal of Zoology, 2010Co-Authors: A. R. McveanAbstract:Autotomy is the specific action by which a limb of an animal is rejected by a reflex action. In Carcinus maenas (L.) any single pereiopod may be rejected following gross inflicted damage. Tension measurements of the muscles involved in this action indicate that previous accounts of the mechanism of autotomy cannot be entirely correct. There are two basi-ischiopodite levators of which the anterior one is by far the larger. This muscle is responsible for both walking movements and autotomizing the limb but both actions are reliably separated as autotomy requires the specific intervention of the posterior levator. The tendon of the posterior levator rests against that of the anterior levator. Rotation of the posterior levator tendon separates a hitherto unsuspected preformed breakage plane in the tendon of the anterior levator which radically alters the action of this muscle. The mechanism proposed here by which autotomy in Carcinus maenas is effected, shows that the shedding of a limb is a specific act and not merely an extension of a normal limb movement as has been supposed.
