Water fleas

Aquatic toxicity is reported in mg/L for Pimepha/espromealas (fathead minnow), 69-h LC q 7650 (17) for Daphnia magna (water flea), 48-h EC q 3310 (18) for Mjriophjllum spicatum (water milfoil), phytotoxicity (EC q for growth) 5962 (19) and for Pana breviceps (frog), no observed effect concentration (NOEC) 400 (20). LC q and EC q are lethal and effect concentrations, respectively, for 50% of the subjects tested. 

Finally, the Aquatic Toxicity module predicts fish and daphnia toxicity providing LC50 values (mg/L) for Pimephales promeals (Fathead minnow) and Daphnia magna (Water flea). Experimental values (if present) and similarity to test compound are shown for the five most similar structures from the training set [65]. 

The communities include in particular bacteria, lower aquatic plants (algae), higher aquatic plants, organisms fish feed on (e.g. water flea, amphipods etc.) and fish. They participate in the self purification of waters (reduction of residual pollution from effluent discharges like industrial drainage) and maintain the natural biological equilibrium. 

Zou, E. and S. Bu. 1994. Acute toxicity of copper, cadmium, and zinc to the water flea, Moina irrasa (Cladocera). Bull. Environ. Contam. Toxicology 52 742-748. 

Karen, D.J., D.R. Ownby, B.L. Forsythe, T.P. Bills, T.W. La Point, G.B. Cobb, and SJ. Klaine. 1999. Influence of water quality on silver toxicity to rainbow trout (Oncorhynchus mykiss), fathead minnows (Pimephales promelas), and water fleas (Daphnia magnet). Environ. Toxicol. Chem. 18 63-70. 

Khangarot, B.S. and P.K. Ray. 1989. Investigation of correlation between physicochemical properties of metals and their toxicity to the water flea Daphnia magna Straus. Ecotoxicol. Environ. Safety 18 109-120. 

Macek, K.J., M.A. Lindberg, S. Sauter, K.S. Buxton, and P.A. Costa. 1976. Toxicity of Four Pesticides to Water Fleas and Fathead Minnows. U.S. Environ. Protection Agen. Rep EPA-600/3-76-099. 57 pp. Macko, V., J.A.A. Renwick, and J.F. Rissler. 1978. Acrolein induces differentiation of infection structures in the wheat stem rust fungus. Science 199 442-443. 

Early studies focused on how adsorption to sediments affected the toxicity of SPs to aquatic organisms, through modifying exposure. It was shown for example that when permethrin and cypermethrin were adsorbed to sediments, the apparent toxicities to the water flea (D. magna), the mayfly nymph (Cloeon dipterum), and bluegill sunfish (Lepomis macrochirus) were significantly reduced [5]. 

The rate of development of the water flea (Alona affinis) from egg to adult is activated, since a plot of ln(development rate) (as y ) against 1 IT (as x )... 

Water flea Daphnia magna Mosquito Culex pipiens quinquefasciata Stonefly... 

The available information about LAS toxicity on freshwater organisms is very extensive. The water flea (Daphnia magna) is the most frequently employed species in freshwater acute toxicity tests. 

Bobra, A., Shiu, W. Y.. and Mackay. D. A predictive correlation for the acute toxicity of hydrocarbons and chlorinated hydrocarbons to the water flea. Chemosphere, 12(9-10) 1121-1129, 1983. 

LeBlanc, G.A. Acute toxicity of priority pollutants to water flea Daphnia magna), Bull. Environ. Contam. Toxicol, 24(5) 684-691, 1980. 

Effects assessment, by, as in the case of risk assessment for chemicals and pesticides, determining a set of marker organisms (including algae, zebrafish, insect larvae, benthic worm, water flea, etc.) that represent ecosystem components and food networks and are used to indicate acute and chronic effects. This step is also used to define the predicted no-effect concentrations (PNECs). 

The examples of the attribution of the real sewage sludge formed on different treatment plants to the classes of hazard are presented in Table 7. The same approach was adopted in Russia for the attribution of the waste as a whole to the classes of hazard. The only difference is the use of the test organisms representing water life (water flea, algae, protozoa) [174]. 

In 1957, Schwartz and associates showed that the toxic element selenium was also a nutritional factor essential for prevention of the death of liver cells in rats.527 Liver necrosis would be prevented by as little as 0.1 ppm of selenium in the diet. Similar amounts of selenium were shown to prevent a muscular dystrophy called "white muscle disease" in cattle and sheep grazing on selenium-deficient soil. Sodium selenite and other inorganic selenium compounds were more effective than organic compounds in which Se had replaced sulfur. Keshan disease, an often fatal heart condition that is prevalent among childen in Se-deficient regions of China, can be prevented by supplementation of the diet with NaSe03.528 Even the little crustacean "water flea" Daphnia needs 0.1 part per billion of Se in its water.529... 

Daphnia pulex (water flea) Ceriodaphnia dubia (water flea)... 

DNT Isomer J - I tuucau ivimiiuwo (96-hr LC50, mg/fi) Water Fleas (48-hr EC50, mg/fi)... 

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