GROWTH AND REPRODUCTION OF THE EARTHWORM EISENIA-FETIDA EXPOSED TO SUBLETHAL CONCENTRATIONS OF ORGANIC-CHEMICALS

The determination of a short-term LC50 toxicity value for a chemical is a useful indicator of the potential biological effect of the chemical if released into the environment. However, it is possible that adverse effects of the chemical may occur at sublethal concentrations far below LC50 values. Using the earthworm Eisenia fetida (Savigny) as an indicator organism for soil ecosystems, concentrations of 10 organic chemicals were evaluated for sublethal effects on earthworm growth and reproduction. Following short-term exposure to sublethal concentrations of carbaryl and dicldrin, E. fetida was allowed to resume growth and reproduction to determine whether such effects were permanent. The effect on earthworm populations as a representative soil organism could be a sentinel for the effects of more destructive soil processes. © 1990.