Toxicological Responses of the Earthworm Eisenia fetida to 18-Crown-6 Under Laboratory Conditions

The earthworm Eisenia fetida was exposed to artificial soil supplemented with 18-crown-6 (1,4,7,10,13,16-hexaoxacyclooctadecane) to investigate its effects on earthworm mortality, growth, avoidance, burrowing behavior and respiration. The results revealed that 18-crown-6 had the potential to negatively affect the behavior of earthworms. The 7-d LC₅₀ was 585 mg kg⁻¹ soil. Avoidance behavior was the most sensitive endpoint, with a 48-h EC₅₀ of 120 mg kg⁻¹ soil. Growth, burrow length and respiration showed general decreases with increasing 18-crown-6 concentrations. Behavioral endpoints and respiration may be regarded as sensitive parameters in evaluating the toxicity of this chemical to earthworms.