Cladoceran crustaceans

Invertebtates Daphnotoxlit F magna Cladoceran crustacean, Daphnia magna [91]... 

Freshwater cladocerans and marine crustaceans were the most sensitive groups tested, with LC50 (96 h) values of less than 2 pg/L for the more sensitive species (Table 16.2). European eels (.Anguilla anguilla), rainbow trout (Oncorhynchus mykiss), and bluegills (.Lepomis macrochirus) seemed to be the most sensitive freshwater teleosts tested, with LC50 (96 h) values between 80... 

Inhibited adult emergence by 95-100% of a gnat (Chaoborus astictopus), 2-7 days after treatment. Crustacean zooplankton suppressed at all treatment levels, especially cladocerans and copepods. Rotifers and algae were not affected. Bluegills that fed predominantly on cladocerans and copepods switched to chironomid midges and terrestrial insects after treatment, with no adverse effects... 

The toxicity of pentaerythritol tetranitrate (PETN) was higher to bacteria than crustaceans, with a 30-min EC50of 46 pmoles L 1 in the Microtox test [30] (Table 4.6). Tests with the estuarine copepod N. spinipes and freshwater cladoceran D. magna resulted in 96- and48-h LC50 andEC50 values >101 and >155 pmoles I., respectively [13],... 

The mucous feeders can retain cells as small as 1 /xm in diameter, and are relatively unselective as to the particles they retain, except perhaps in the smallest categories (2,3,4). The crustaceans generally capture cells greater than or equal to 5 /xm, though some cladocerans can remove finer material (18), as can appendicularians (1,8). Studies of copepods that were fed suspensions of a single type of cell have generally indicated saturation kinetics. The animal filters a large amount of water when phytoplankton is scarce, and this amount decreases when cells are more... 

MF may also be involved in mediating various stress responses. Hemolymph levels of the hormone rise after challenges with heat stress, hypoxia, and hypo- and hypersalinity. It is unknown how MF helps the crustacean cope with these environmental stresses. MF also acts as a sex determinant. In the cladoceran Daphnia magna, application of physiological amounts of exogenous MF to egg-maturing females resulted in all-male broods. 

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