title: Effect of mosquito killer insecticides on freshwater mussels.
abstract: The effect of four insecticides (Fyfanon, K-Othrin, Unitox 7 and Unitox 20) was investigated on the freshwater mussels Anodonta cygnea L., Anodonta anatina L. and Unio pictorum L. The studies were performed in hard water (total salinity of 310 mg/l). The LC50 values for 24, 48, 72, 96 hr and 7 days were determined with a static test at 22 degrees C. All the three mussel species proved to be extremely tolerant against the insecticides tested. The effect of sublethal concentrations of these insecticides on the periodic activity of the mussels was also analyzed, comparing the changes of the active and resting periods. In a concentration of 0.1 microliter/l, all the four insecticides affected the periodic activity of U. pictorum, whereas in A. anatina three of them (Fyfanon, K-Othrin and Unitox 7) and in A. cygnea two of them (K-Othrin and Unitox 7) evoked alterations. This concentration is lower by three to five orders than those of the LC50 values of 96 hr.
mesh_terms: D000818:Animals; D049872:Bivalvia / Q000502:physiology*; D001835:Body Weight / Q000187:drug effects; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D009033:Culicidae; D007306:Insecticides / Q000633:toxicity*
chemical_list: D007306:Insecticides