title: Life cycle responses of the midge Chironomus riparius to compounds with different modes of action.
abstract: Compounds with different modes of action may affect life cycles of biota differently. The aim of the present study was therefore to investigate the impact of four chemicals with different modes of action, including the essential metal copper, the nonessential metal cadmium, the organometal tributyltin, and the polycyclic aromatic compound phenanthrene, on chronic lethal and sublethal life-cycle effect parameters of the nonbiting midge Chironomus riparius, applying a 28-day sediment toxicity test. Tributyltin and cadmium delayed emergence significantly over a wide range of sublethal concentrations, while this range was narrow for copper and almost absent for phenanthrene. The chronic LC50/LOECEmT50 ratio, expressing these differences, amounted to 1.5, 3.5, 12.0, and 18.2 for respectively phenanthrene, copper, cadmium, and tributyltin. Thus the more specific the compounds mode of action, the higher the chronic LC50/LOECEmT50 ratio, as previously observed for acute-to-chronic ratios (ACRs). Comparison of our results with literature derived LC50/LOEC ratios showed a comparable trend and a lower variability compared to ACRs. We therefore conclude that the presently proposed chronic ratio is indicative for the specificity of a chemicals mode of action and that it is less variable than the ACR.
authors.affiliation: Department of Aquatic Ecology and Ecotoxicology, Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Sciencepark 904, 1098 XH Amsterdam, The Netherlands. M.Marinkovic@uva.nl
authors.forename: Marino
authors.initials: M
authors.lastname: Marinković
authors.forename: Rudo A
authors.initials: RA
authors.lastname: Verweij
authors.forename: Grietje A
authors.initials: GA
authors.lastname: Nummerdor
authors.forename: Martijs J
authors.initials: MJ
authors.lastname: Jonker
authors.forename: Michiel H S
authors.initials: MH
authors.lastname: Kraak
authors.forename: Wim
authors.initials: W
authors.lastname: Admiraal
mesh_terms: D000818:Animals; D002683:Chironomidae / Q000187:drug effects* / Q000502:physiology; D007928:Lethal Dose 50; D008018:Life Cycle Stages; D014873:Water Pollutants / Q000494:pharmacology* / Q000633:toxicity
chemical_list: D014873:Water Pollutants