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A method to determine the susceptibility of Mesocyclops aspericornis to insecticides is proposed. Tests were carried out by placing adults females in 100 ml of insecticide solution at 3 temperatures (20 degrees C, 25 degrees C, 30 degrees C). Mortality was scored 24 h after treatment. The results show a low variability of the insecticide effectiveness at these temperatures.

Human chorionic gonadotrophin (HCG) stimulates the rate of vitellogenin synthesis and release by fat bodies in puberal females of the marine Crustacean isopods Idotea balthica basteri. Moreover this effect is specific for vitellogenin: since 48 hr after the treatment, the rate of total protein synthesis, in treated females, is not significantly different from that of females injected with physiological medium, or with denaturated gonadotrophin.

The utilization of marine amphipods Podocerus fulanus and Corophium acherusicum, and the marine isopod Paracerceis sculpta in heavy metal toxicity tests (Cd and Cu) demonstrated on the one hand, the value of these animals as tests subjects when exposed to various polluting agents and, on the other hand their tolerance to heavy metals in acute toxicity tests.

The effects of three metal salts (BaCl2, CuCl2, ZnCl2) and of N-trityl-morpholine (Triphenmorph) were studied on two aquatic amphipod species, Gammarus pulex and Echinogammarus berilloni. Experiments were made up in eucalcic and oligocalcic waters for determining the LC50 at different exposure times. The order of toxicity was the same in eucalcic water with the two species: Triphenmorph greater than Cu2+ greater than Zn2+ greater than Ba2+. This order was the same in oligocalcic water with Echinogammarus berilloni; with Gammarus pulex, CuCl2 was more toxic than Triphenmorph.

The animals stay in solutions for 4 days at different concentrations of each agent: regression lines (log concentration-probit) allow us to calculate the lethal concentration values for 50% of the animals tested (LC 50). Animals are affected by concentrations ranging from 0,003 to 9,0 X 10(-6) of insecticides, 2 to 16 X 10(-6) of herbicide, 9 to 50 X 10(-6) of detergents. As a general rule, the four studied species can be classified by decreasing sensibility in the following order: Gammarus, Cloeon, Chaoborus and Lymnea.