カイアシ類, ミジンコ類及びワムシ類に対する内分泌かく乱化学物質の急性毒性濃度

Reports have been increasing on the deleterious effect of endocrine disrupting compounds (EDCs) on marine inhabitants. Zooplankton, the primary consumer in the aquatic ecosystem are not spared on these effect. As a first step to investigate the chronic and reproductive effects of EDCs on marine zooplankton, we determined the acute toxic concentration of the known and suspected EDCs for vertebrates including two natural hormone (testosterone, 17β-estradiol), three estrogenic compounds (nonylphenol, octylphenol, bisphenol A), six pesticides (isoprothiolane, methoprene, fenitrothion, diazinon, iprofenfos, pyroquilon) and a herbicide (mefenacet) on the copepod Tigriopas japonicus, the cladoceran Diaphanosoma celebensis and the rotifer Brachionus plicatilis. Compound exposure was carried out in 6-well polysterene plates, and mortality was evaluated after 24 h. Although the three zooplankton depicted different sensitivities toward different compounds, a dose-response relationship was consistent in all cases. B. plicatilis was particularly resistant to most of the compounds tested, while T. japonicl.ls and D. celebensis are comparatively sensitive. The data presented herein can be a basis for the determination of concentrations to be used in chronic and endocrine disruption experi-ments using marine zooplankto