title: A comparative study of insecticide toxicity among seven cladoceran species.
abstract: The sensitivities of seven cladoceran species (Ceriodaphnia reticulata, Chydorus sphaericus, Daphnia galeata, Diaphanosoma brachyurum, Moina macrocopa, Scapholeberis kingi, and Simocephalus vetulus) to carbamate insecticides (carbaryl and methomyl) were investigated by acute toxicity tests. The sensitivities to carbaryl and methomyl were highly correlated among the tested organisms, but the co-tolerance level varied markedly among species. C. reticulata showed the highest sensitivity, whereas M. macrocopa and S. kingi showed the lowest sensitivities to the two insecticides. These results indicate that the degree of chemical impacts on natural communities can vary depending on cladoceran species composition. The highly positive correlation between the EC(50) values for both insecticides indicates that the two chemicals have a shared mode of action on cladoceran species. Unlike previous reports, acute toxicity was not correlated with body size. The results are discussed in relation to community-level experiments, the functions of freshwater ecosystems, and ecological risk assessment.
authors.affiliation: Research Center for Environmental Risk, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba 305-8506, Japan. mano.hiroyuki@nies.go.jp
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Mano
authors.forename: Masaki
authors.initials: M
authors.lastname: Sakamoto
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Tanaka
mesh_terms: D000818:Animals; D049628:Body Size / Q000187:drug effects; D002219:Carbamates / Q000633:toxicity*; D033361:Cladocera / Q000187:drug effects* / Q000378:metabolism; D017753:Ecosystem; D005618:Fresh Water; D007306:Insecticides / Q000633:toxicity*; D018570:Risk Assessment / Q000379:methods; D013045:Species Specificity; D023382:Toxicity Tests, Acute; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D002219:Carbamates; D007306:Insecticides; D014874:Water Pollutants, Chemical