INTRASPECIES VARIATION IN LETHAL BODY BURDENS OF NARCOTIC COMPOUNDS

Groups of fathead minnows were exposed to different concentrations of di- or trichlorobenzenes, tetrachloroethane or PCBs. Lethal body burde ns (LBB, mmol compound/kg wet weight) were determined. The purpose of the study was to obtain information on the variability of the LBB with in a population, and on the reasons for this variability. The variatio n in LBB within a population was 4- to 23-fold for the chemicals teste d. Approximately 50% of this variation could be attributed to the lipi d content of the individuals. The LBB did not depend on the weight of the fish. The exposure time until lethality did not influence the LBB for the di- and trichlorobenzenes and tetrachloroethane. In contrast, the LBB of the PCBs was influenced by this parameter, a shorter exposu re time resulting in a lower LBB.