السمية الحادة لمبيد الأعشاب Dichlorophenoxyacetic Acid-2,4 على إناث برغوث الماء Daphnia Magna وتأثير السمية المزمنة في بناء الجدول الحياتي = The Acute Toxicity of 2,4-Dichiorophenoxyacetic Acid Herbicide on a Water Flea Females Daphnia Magna and the Effect of Chronic Toxicity in Building Life Tables

Previous studies have shown that the crude ethanol extract and its ethylacetate fraction of the plant Eupatorium fortunei Turcz strongly inhibited the growth of a harmful freshwater cyanobacterium Microcystis aeruginosa. However, the perspective of using these plant extracts as alternative algicides takes into account their potential risks to other species in aquatic ecosystems, including Daphnia magna. The current study presents the acute toxicity of the extracts to D. magna. The median lethal concentrations, immobilizing 50 % of D. magna, (LC50) after 24 and 48 h of the ethanol extract were 247 and 183 mg L-1, respectively. In the exposure to ethyl acetate fraction, the values of 24h-LC50 and 48h-LC50 were 47 and 13 mg L-1, respectively. The values of dissolved oxygen (DO) and pH in the control and treatments had little change during the 48-hour experiment period, fluctuating from 6.44 ÷ 7.90 and 6.07 ÷ 7.78 mg L-1, respectively, and they were still good conditions for D.magna growth. Finally, these results prove clearly that the ethyl acetate fraction is more toxic to the freshwater cladoceran than the ethanol extract. To our knowledge, it is the first report of the acute toxic estimation of E. fortunei extracts to zooplankton species, D. magna. Chronic toxicity of these extracts to D. magna needs to be studied in next step.

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First evidence for an aposematic function of a very common color pattern in small insects

10.1101/2020.07.27.222653 ◽

2020 ◽

Author(s):

Rebeca Mora-Castro ◽

Marcela Alfaro-Córdoba ◽

Marcela Hernández-Jiménez ◽

Mauricio Fernández Otárola ◽

Michael Méndez-Rivera ◽

...

Keyword(s):

Statistical Analysis ◽

Acute Toxicity ◽

Daphnia Magna ◽

Reflection Spectrum ◽

Behavioral Responses ◽

Color Pattern ◽

Parasitoid Wasps ◽

Water Flea ◽

Warning Coloration ◽

Absorption Contrast

AbstractMany small parasitoid wasps have a black-orange-black (BOB) color pattern, which is usually present in both sexes. A likely function of this widespread pattern is aposematic (warning) coloration, but this has never been investigated. To test this hypothesis, we presented spider predators (Lyssomanes jemineus), both field-captured and lab-reared individuals, to a species with the BOB pattern and a congeneric all-black species in each of four scelionid genera (Baryconus, Chromoteleia, Macroteleia and Scelio). Each spider/wasp trial was filmed for 40 minutes under controlled conditions and three behavioral responses (detect, attack, avoid) were recorded in each of 136 trials, never using the same predator and prey more than once. In order to better understand the results obtained, two additional studies were performed. First, the reflection spectrum of the cuticle of the wasp and a theoretical visual sensibility model of the spider were used to calculate a parameter we called “absorption contrast” that allowed us to compare the perception contrast between black and orange in each wasp genus as viewed by the spider. Second, acute toxicity trials with the water flea, Daphnia magna, were performed to determine toxicity differences between BOB and non-BOB wasps. By combining the results from the three types of experiments, together with a statistical analysis, we confirmed that BOB color pattern plays an aposematic role.

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Acute Toxicity of Pozzolanic Cement on Two Crustacean Species, Water Flea (Daphnia magna) and Gammarus komareki

Bulletin of Environmental Contamination and Toxicology ◽

10.1007/s00128-021-03345-x ◽

2021 ◽

Author(s):

Akif Er ◽

Şevki Kayış

Keyword(s):

Acute Toxicity ◽

Daphnia Magna ◽

Water Flea ◽

Crustacean Species ◽

Pozzolanic Cement

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Acute toxicity of carbofuran to selected species of aquatic and terrestrial organisms

Plant Protection Science ◽

10.17221/3865-pps ◽

2011 ◽

Vol 39 (No. 3) ◽

pp. 103-108 ◽

Cited By ~ 15

Author(s):

R. Dobšíková

Keyword(s):

Acute Toxicity ◽

Daphnia Magna ◽

Poecilia Reticulata ◽

Aquatic Organisms ◽

Sinapis Alba ◽

Agricultural Practice ◽

White Mustard ◽

Water Flea ◽

Raphidocelis Subcapitata ◽

The World

Carbofuran is an anticholinesterase carbamate commonly used as an insecticide, nematicide and acaricide in agricultural practice throughout the world. The aim of the study was to investigate the acute toxicity of carbofuran to selected species of aquatic organisms (the guppy Poecilia reticulata Peters, the water flea Daphnia magna Straus and the green alga Raphidocelis subcapitata Korsikov), and to a terrestrial organism (a white mustard Sinapis alba Linné). Daphnia magna Straus was found to be the most sensitive organism.    

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