Results 191 to 200 of about 76,951 (232)

Effect of Lindane on the Clearance Rate of Daphnia magna

Archives of Environmental Contamination and Toxicology, 1999
The impact of the insecticide lindane (gamma-hexachlorocyclohexane) on the clearance rate (CR) of Daphnia magna was investigated using artificial beads. CR (24-h EC50: 65 &mgr;g L-1) was found to be a more sensitive endpoint than acute lethality for D. magna (48-h LC50: 516 &mgr;g L-1).
Hartgers, E.M., Heugens, E.H.W., Deneer, J.W.   +2 more
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Breeding Daphnia magna

Hydrobiologia, 1978
This paper deals with some methods for breeding Daphnia magna. Critical variables are the filtration of the medium on charcoal, the composition of the medium, the amount of food, the addition of vitamins with yeast extract and the extent of refreshing the medium. If these variables are well controlled, breeding daphnia is easy with reproduction varying
openaire   +1 more source

Sub-lethal effects of acetone on Daphnia magna

Ecotoxicology, 2007
There is increasing concern about the sub-lethal effect of hydrophobic chemicals in the water medium. Even though acetone is a commonly used solvent in toxicity testing, few studies have focussed on its chronic toxicity to Daphnia magna and the available results are often contradictory. In this study, acetone was tested on D. magna in a 21-day exposure
LEONI, BARBARA, Bettinetti, R, Galassi, S.   +2 more
openaire   +3 more sources

Haemoglobin in male Daphnia magna

Comparative Biochemistry and Physiology Part A: Physiology, 1989
Abstract 1. 1. To define the respiratory function of haemoglobin in male Daphnia magna , the swimming activity, the depression of oxygen uptake by treatment with carbon monoxide and in vivo oxygenation of Hb at various oxygen pressures were investigated. 2. 2. The P 50 , values for the purified Hbs from male and female red animals were 2.
Kobayashi Michiyori, Tanaka Yuko, Ninomiya Masaki, Fujiki Masahiko, Ochiai Takehiko   +4 more
openaire   +1 more source

Intersex and male development in Daphnia magna

Hydrobiologia, 2001
Sex induction is environmentally stimulated in Daphnia and involves a cue-dependent response for sex determination. Somatic growth was shown to be similar in males and females during juvenile instars, but divergent due to a reduction in male somatic growth, at about the time that females produce ovaries.
openaire   +2 more sources

Thermal avoidance and preference in Daphnia magna

Journal of Thermal Biology, 2000
Abstract 1. Water fleas (Daphnia magna) bred at 23°C were non-responsive to temperatures between 13 and 25°C. 2. At the lower (11°C) and upper limits (30°C) their klinokinetic avoidance behaviour showed a larger intraindividual than interindividual variation. 3. Thermal sensitivity for avoidance responses in D. magna was about 1.5°C. 4.
openaire   +2 more sources

The effects of nonylphenol on Daphnia magna

Water Research, 1993
Abstract The acute and chronic toxicity of nonylphenol to the freshwater invertebrate Daphnia magna has been determined. The acute 24 and 48 h EC 50 values, based on immobilization, were 0.30 and 0.19 mg/l, respectively, using mean measured concentrations.
M.H.I. Comber, T.D. Williams, K.M. Stewart   +2 more
openaire   +1 more source

Cadmium resistance in Daphnia magna

Aquatic Toxicology, 1990
Abstract The potential of the water-flea Daphnia magna to develop resistance to cadmium was investigated. Three successive generations of daphnids were exposed to sublethal cadmium concentrations, and thereafter the cadmium resistance was assessed in acute LC50-tests. Resistance to cadmium was found to be acquired during a single generation.
C.W.M. Bodar, I. van der Sluis, J.C.P. van Montfort, P.A. Voogt, D.I. Zandee   +4 more
openaire   +1 more source

Toxicity of uranium to Daphnia magna

Water, Air, and Soil Pollution, 1984
The toxicity of U to Daphnia magna was determined in acute and chronic tests. The 48-hr LC50 of U (VI) in Columbia River water was 6 mg L−1. Acute toxicity diminished by a factor of 7.5 as mean water hardness and alkalinity values increased from 70 mg L−1. and 57 mg L−1. to 195 mg L−1. and 130 mg L−1. respectively.
T. M. Poston, R. W. Hanf, M. A. Simmons
openaire   +1 more source

Sex Determination in Daphnia Magna

Ecology, 1990
The factors inducing male offspring and the mechanism of sex—ratio adjustment were investigated in Daphnia magna, a cyclically parthenogenetic cladoceran (Crustacea). Laboratory experiments were conducted on individual animals living in flow—through chambers, to separate the effects of various density—dependent factors.
Anders Hobaek, Peter Larsson
openaire   +1 more source