Stress Indicators and Behavioural End-Points of Lybriodrillus violaceous Exposed to Petroleum Products Contaminated Soil

摘要

The effect of fresh gasoline contaminated soil (GS), fresh diesel contaminated soil (DS) and a 3 years old oil spill soil on indigenous tropical earthworm, Lybiodrillus violaceous, was carried out using five acute toxicity tests. This included coiling exhibition, swollen clitellium, 14 days survival test, 48hrs avoidance response test and 56 days juvenile production test. Soil samples from a non-contaminated soil (NCS) were used as control. The exposure of earthworms to GS and DS soils resulted in exhibition of coiling response and swollen clittelium region. For survival test, results showed 60% and 20% survival for GS and DS respectively while 80% and 100% survival were recorded for CS and NCS. Avoidance test showed that there was 8:2 (NCS:DS), 6:4 (NCS:GS) and 5:5 (NCS:CS) ratio of L.violaceous present in soil types. Study on Juvenile production showed that there were no juveniles produced in both GS and DS contaminated soil, however, there were juvenile production recorded in CS and NCS. The negative impact of all toxicity tests on L.violaceous was more in diesel contaminated soil compared to gasoline contaminated soil and least in the 3 year old spill soil. The results indicated negative effect of diesel and gasoline contamination on L.violaceous.