scholarly journals Effects of Single and Combined Low Concentrations of Neuroactive Drugs on Daphnia magna Reproduction and Transcriptomic Responses

2019 ◽  
Vol 53 (20) ◽  
pp. 11979-11987 ◽  
Author(s):  
Inmaculada Fuertes ◽  
Bruno Campos ◽  
Claudia Rivetti ◽  
Benjamín Piña ◽  
Carlos Barata
Keyword(s):  
Daphnia Magna ◽  
Low Concentrations ◽  
Neuroactive Drugs ◽  
Transcriptomic Responses

The joint acute toxicity to Daphnia magna of industrial organic chemicals at low concentrations

1988 ◽  
Vol 12 (1) ◽  
pp. 33-38 ◽  
Author(s):  
J.W. Deneer ◽  
T.L. Sinnige ◽  
W. Seinen ◽  
J.L.M. Hermens
Keyword(s):  
Acute Toxicity ◽  
Daphnia Magna ◽  
Organic Chemicals ◽  
Low Concentrations

scholarly journals Impact of polystyrene microplastics on Daphnia magna mortality and reproduction in relation to food availability

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4601 ◽  
Author(s):  
Rana Aljaibachi ◽  
Amanda Callaghan
Keyword(s):  
Food Intake ◽  
Daphnia Magna ◽  
Chlorella Vulgaris ◽  
Negative Impact ◽  
Freshwater Environment ◽  
Aquatic Life ◽  
Low Concentrations ◽  
Significant Negative Impact ◽  
Area Of Concern ◽  
The Impact

Microplastics (MPs) in the environment continue to be a growing area of concern in terms of acute and chronic impacts on aquatic life. Whilst increasing numbers of studies are providing important insights into microparticle behaviour and impacts in the marine environment, a paucity of information exists regarding the freshwater environment. This study focusses on the uptake, retention and the impact of 2 µm polystyrene MPs in the freshwater cladoceran Daphnia magna in relation to food intake (algae Chlorella vulgaris), with MP size chosen to approximately match the cell size of the algae. Daphnia were exposed to varied concentrations of MPs and algae. When exposed to a single concentration of MPs Daphnia almost immediately ate them in large quantities. However, the presence of algae, even at low concentrations, had a significant negative impact on MP uptake that was not in proportion to relative availability. As MP concentrations increased, intake did not if algae were present, even at higher concentrations of MPs. This suggests that Daphnia are selectively avoiding eating plastics. Adult Daphnia exposed to MPs for 21 days showed mortality after seven days of exposure in all treatments compared to the control. However significant differences were all related to algal concentration rather than to MP concentration. This suggests that where ample food is present, MPs have little effect on adults. There was also no impact on their reproduction. The neonate toxicity test confirmed previous results that mortality and reproduction was linked to availability of food rather than MP concentrations. This would make sense in light of our suggestion that Daphnia are selectively avoiding eating microplastics.

scholarly journals The Physiological and Biochemical Responses of Daphnia magna to Dewatered Drinking Water Treatment Residue

2020 ◽  
Vol 17 (16) ◽  
pp. 5863 ◽  
Author(s):  
Nannan Yuan ◽  
Yuansheng Pei ◽  
Anping Bao ◽  
Changhui Wang
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Daphnia Magna ◽  
Environmental Remediation ◽  
Chronic Toxicity ◽  
Drinking Water Treatment ◽  
Toxicity Tests ◽  
Physiological And Biochemical Characteristics ◽  
Low Concentrations ◽  
Physiological And Biochemical

There have been widespread attempts to recycle drinking water treatment residue (DWTR) after dewatering for environmental remediation, which is beneficial for both the environment and the economy. The directly discharged DWTR without dewatering to natural water bodies, however, was reported to show signs of chronic toxicity to Daphnia magna (D. magna), a typical zooplankton in the aquatic environment. This study comprehensively assessed the effect of dewatered DWTR on the physiological and biochemical characteristics of D. magna based on acute and chronic toxicity tests. The results showed that the survival, growth, reproduction, body morphology of offspring, and the antioxidant enzymes of D. magna were not affected by the dewatered DWTR. These physiological and biochemical indexes also had no undesirable changes for the DWTR-amended sediments (with ratios of 0–50%) incubated for 10 and 180 d; the growth and reproduction were even promoted when D. magna was exposed to 5000 mg-sediment L−1, which may be due to the extra nutrients supplied by the amended sediments for the animals. The results demonstrated that by contrast with the directly discharged DWTR without dewatering, the dewatered DWTR could be safe to D. magna. Further analysis suggested that heavy metals (Pb, Ni, Cu, Cr, and Zn) with relatively low concentrations and high stability could be the main reasons leading to the high safety of the dewatered DWTR. Overall, dewatered DWTR can be considered a non-hazardous material for zooplankton.

scholarly journals Species-specific transcriptomic responses in Daphnia magna exposed to a bio-plastic production intermediate

2019 ◽  
Vol 252 ◽  
pp. 399-408
Author(s):  
Elmer Swart ◽  
Tjalf E. de Boer ◽  
Guangquan Chen ◽  
Riet Vooijs ◽  
Cornelis A.M. van Gestel ◽  
...  
Keyword(s):  
Daphnia Magna ◽  
Transcriptomic Responses ◽  
Species Specific

Survival, Respiration, and Food Assimilation of Daphnia magna Exposed to Petroleum- and Coal-Derived Oils at Three Temperatures

1983 ◽  
Vol 40 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Sterling O. Ullrich Jr. ◽  
Raymond E. Millemann
Keyword(s):  
Acute Toxicity ◽  
Daphnia Magna ◽  
Diesel Oil ◽  
Water Soluble ◽  
Fuel Oil ◽  
Toxicity Tests ◽  
Respiration Rates ◽  
Low Concentrations ◽  
Food Assimilation ◽  
Sublethal Concentrations

Acute toxicity tests with the water-soluble fractions (WSFs) of both oils showed that mortality of Daphnia magna was directly related to temperature and the WSF concentration. The coal-derived oil was more toxic than the diesel fuel oil. The 48-h LC50s for the former were 0.70, 0.44, and 0.18% at 10, 20, and 25 °C, respectively; the values for the diesel oil WSF were 87, 32, and 9.7% at 10, 20, and 25 °C, respectively. Respiration rates of animals exposed to sublethal concentrations of the WSFs at 10, 20, and 25 °C were significantly affected by the WSF concentration of the oils and temperature. The interaction between the concentration of each oil with temperature was statistically significant. Low concentrations of diesel oil WSF stimulated respiration rates at each temperature, but higher concentrations depressed them. At all temperatures, oxygen consumption rates of animals exposed to the coal-derived oil WSF decreased with increased concentration. The exposure to sublethal concentrations of both oils affected food assimilation of the animals in a manner similar to that observed when respiration was the criterion of toxic effect. The interaction between diesel oil WSF concentrations and temperature, but not between coal oil WSF concentrations and temperature, was statistically significant. At 20 and 25 °C, low concentrations of diesel oil WSF stimulated assimilation rates, whereas low concentrations of the coal oil WSF depressed them. Generally, high concentrations of both WSFs depressed assimilation rates below control values. These results emphasize the importance of natural stresses, such as temperature, in enhancing toxicity of synthetic chemicals to aquatic organisms, and they reinforce the need to consider such variables as season of the year in evaluating biotic effects of oil spills.Key words: temperature, Daphnia magna, petroleum, coal oil, synthetic oil, respiration, food assimilation, acute toxicity, chronic toxicity

Microtubule nucleation sequence studied by time-resolved x-ray scattering and electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 766-767
Author(s):  
Eva-Maria Mandelkow ◽  
Eckhard Mandelkow ◽  
Joan Bordas
Keyword(s):  
Electron Microscopy ◽  
Dynamic Equilibrium ◽  
Time Resolved ◽  
X Ray ◽  
Additional Information ◽  
X Ray Scattering ◽  
Low Concentrations ◽  
Microtubule Growth ◽  
Ray Patterns ◽  
Ray Scattering

When a solution of microtubule protein is changed from non-polymerising to polymerising conditions (e.g. by temperature jump or mixing with GTP) there is a series of structural transitions preceding microtubule growth. These have been detected by time-resolved X-ray scattering using synchrotron radiation, and they may be classified into pre-nucleation and nucleation events. X-ray patterns are good indicators for the average behavior of the particles in solution, but they are difficult to interpret unless additional information on their structure is available. We therefore studied the assembly process by electron microscopy under conditions approaching those of the X-ray experiment. There are two difficulties in the EM approach: One is that the particles important for assembly are usually small and not very regular and therefore tend to be overlooked. Secondly EM specimens require low concentrations which favor disassembly of the particles one wants to observe since there is a dynamic equilibrium between polymers and subunits.

Membrane-bound vesicles associated with the microvilli in the midgut of the freshwater microcrustacean, Daphnia magna

1983 ◽  
Vol 41 ◽  
pp. 480-481
Author(s):  
Patricia L. Jansma
Keyword(s):  
Daphnia Magna ◽  
Intestinal Epithelial Cells ◽  
Uranyl Acetate ◽  
Intestinal Epithelial ◽  
Chlamydomonas Reinhardii ◽  
Thin Sections ◽  
Saturated Water ◽  
Cacodylate Buffer ◽  
Membrane Bound ◽  
Ethanol Series

The presence of the membrane bound vesicles or blebs on the intestinal epithelial cells has been demonstrated in a variety of vertebrates such as chicks, piglets, hamsters, and humans. The only invertebrates shown to have these microvillar blebs are two species of f1ies. While investigating the digestive processes of the freshwater microcrustacean, Daphnia magna, the presence of these microvillar blebs was noticed.Daphnia magna fed in a suspension of axenically grown green alga, Chlamydomonas reinhardii for one hour were narcotized with CO2 saturated water. The intestinal tracts were excised in 2% glutaraldehyde in 0.2 M cacodyl ate buffer and then placed in fresh 2% glutaraldehyde for one hour. After rinsing in 0.1 M cacodylate buffer, the sample was postfixed in 2% OsO4, dehydrated with a graded ethanol series, infiltrated and embedded with Epon-Araldite. Thin sections were stained with uranyl acetate and Reynolds lead citrate before viewing with the Philips EM 200.

Sign in / Sign up

Export Citation Format

Share Document