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- Berglind, Rune, 1952, et al.
(author)
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THE EFFECTS OF LEAD ON DELTA-AMINOLEVULINIC-ACID DEHYDRATASE ACTIVITY, GROWTH, HEMOGLOBIN CONTENT, AND REPRODUCTION IN DAPHNIA-MAGNA
- 1985
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In: ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY. - 0147-6513. ; 9:2, s. 216-229
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Journal article (peer-reviewed)abstract
- The effects of continuous exposure to lead for various periods and recovery in clean water on δ-aminolevulinic acid dehydratase (ALA-D) activity, hemoglobin content, growth, and reproduction were studied in Daphnia magna. Steady-state inhibition of ALA-D activity was reached within 2 days in 16, 64, and 256 μg Pb liter−1, but restoration in clean water was prolonged in relation to previous exposure. In spite of the inhibition of ALA-D activity hemoglobin content increased after 2 days in 16 and 24 μg Pb liter−1. Furthermore, hemoglobin content in previously exposed animals increased during recovery in clean water. Maximum hemoglobin content (2.9 times control value) was found after 2 days recovery of animals exposed to 64 μg Pb liter−1. These findings suggest that some enzyme(s) other than ALA-D in the biosynthetic pathway of hemoglobin formation is (are) more sensitive to lead. Growth, in contrast to reproduction, was stimulated by low concentrations of lead (<64 μg Pb liter−1), although in 256 μg Pb liter−1 growth was also significantly impaired. After 19 days the 16 and 50% reproductive impairment concentrations were ⩽1 and 10 μg Pb liter−1, respectively.
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- Dave, Göran, 1945
(author)
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Effects of copper on growth, reproduction, survival and hemoglobin in Daphnia magna
- 1984
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In: Comparative Biochemistry and Physiology - Part C: Toxicology & Pharmacology. - 1532-0456. ; 78:2, s. 439-443
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Journal article (peer-reviewed)abstract
- 1. The effects of additions of CuSO4 × 5H2O to final concentrations between 0.0004 and 105μg Cu l− on growth, reproduction, survival and haemoglobin content of Daphnia magna were studied in hard reconstituted water and compared to the response in the dilution water without addition of copper. Concentrations of copper are nominal values. 2. The 48-hr Spec50 (immobilization) for unfed neonates was 6.5 μg Cu l−1 and the 48-hr and 21-day lc50 for fed neonates were 18.5 and 1.4 μg Cu l−1, respectively. 3. Growth expressed as body length of juveniles after 7 days and adult females after 21 days was only reduced in survivors at the highest non-lethal concentration (6.6 μg Cu l−). 4. Reproduction was stimulated by low concentrations of copper. Optimal reproduction after 21 days was found between 0.001 and 0.1 μg Cu l−1. Higher concentrations were partially inhibitory (0.4 μgCu 1−1), stimulatory (0.8 and 1.6 μg Cu l−1) or completely inhibitory (3.2μg Cu l−1 and above). 5. The stimulatory peak around 1 μg Cu l−1 was accompanied by a reduced survival (above 0.4 μg Cu l−1). The Zero Equivalent Point (ZEP) for reproduction at non-reduced survival was 0.23 μg Cu l−1. This concentration should be “safe” for D. magna under prevailing conditions (reconstituted water with a hardness of 250 mg l−1 as CaCo3 and a synthetic diet based on fish food and baby gruel). 6. The haemoglobin content was affected by copper in a complex pattern which was not related to growth, reproduction or survival.
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- Dave, Göran, 1945
(author)
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Effects of fluoride on growth, reproduction and survival in Daphnia magna
- 1984
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In: Comparative Biochemistry and Physiology Part C: Comparative Pharmacology and Toxicology. - 0742-8413. ; 78:2, s. 425-431
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Journal article (peer-reviewed)abstract
- . The effects of waterborne iron (FeCl3 × 6 H2O) on growth, reproduction, survival and haemoglobin content in Daphnia magna were studied from subnormal to toxic concentrations in hard reconstituted water. 2. Low concentrations of iron stimulated reproduction and haemoglobin synthesis after chronic exposure for 21 days. Maximum reproduction occurred between 0.1 and μg Fel−1. 3. Juvenile growth was not stimulated by iron but was slightly inhibited between 1 and 8 μg Fe l−1 and above 128 μg Fe l−1. A slight inhibition of growth persisted for 21 days. 4. Total haemoglobin content was above the control with no waterborne iron at all but one concentration (512 μg Fe l−1). The highest value (3.8 × control value) was found at 2μg Fe l−1. The haemoglobin content decreased between 64 and 512 μg Fe l−1 and increased at higher concentrations. The decrease coincided with an inhibited reproduction. The increase was found in non reproductive survivors. 5. A comparison with a previous study in D. magna suggests that ambient conditions (hardness and pH) and ageing of the water are important for the effects of waterborne iron. At a hardness of 250 mg l−1 as CaCO3 and a pH range of 7.0–8.0 the ZEP (Zero Equivalent Point) for reproduction was 158 μg Fe l−1. Continuous exposure to higher concentrations is expected to lead to extinction of a D. magna population.
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- Dave, Göran, 1945
(author)
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Effects of waterborne iron on growth, reproduction, survival and hemoglobin in Daphnia magna
- 1984
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In: Comparative Biochemistry and Physiology - Part C: Toxicology & Pharmacology. - 1532-0456. ; 78:2, s. 433-438
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Journal article (peer-reviewed)abstract
- 1. The effects of waterborne iron (FeCl3 × 6 H2O) on growth, reproduction, survival and haemoglobin content in Daphnia magna were studied from subnormal to toxic concentrations in hard reconstituted water. 2. Low concentrations of iron stimulated reproduction and haemoglobin synthesis after chronic exposure for 21 days. Maximum reproduction occurred between 0.1 and μg Fel−1. 3. Juvenile growth was not stimulated by iron but was slightly inhibited between 1 and 8 μg Fe l−1 and above 128 μg Fe l−1. A slight inhibition of growth persisted for 21 days. 4. Total haemoglobin content was above the control with no waterborne iron at all but one concentration (512 μg Fe l−1). The highest value (3.8 × control value) was found at 2μg Fe l−1. The haemoglobin content decreased between 64 and 512 μg Fe l−1 and increased at higher concentrations. The decrease coincided with an inhibited reproduction. The increase was found in non reproductive survivors. 5. A comparison with a previous study in D. magna suggests that ambient conditions (hardness and pH) and ageing of the water are important for the effects of waterborne iron. At a hardness of 250 mg l−1 as CaCO3 and a pH range of 7.0–8.0 the ZEP (Zero Equivalent Point) for reproduction was 158 μg Fe l−1. Continuous exposure to higher concentrations is expected to lead to extinction of a D. magna population.
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