摘要：For decades, toxicity studies on earthworms have focused only on the influence of heavy metal while there is little data on the biomarkers response to organic contaminants. Most of the soil toxicity tests have been carried out using epigeic earthworm; however, exposure and effect of these species to soil contamination is sometimes questioned. Thus, current knowledge on the sensitivity and ability of tropical endogeic earthworms to survive in hydrocarbon-polluted soils is limited. The present study aimed to determine the earthworm populations present in soil polluted with weathered crude oil. Earthworm diversity, abundance and biomass, as well as the physical and chemical properties of soil and total oil hydrocarbon content, were determined along a pollution gradient. The findings reveal that the chemical quality of soil decreases significantly with soil depth, and that oil-hydrocarbons are dispersed across the pollution gradient. Earthworm abundance and biomass largely depend on the pollution gradient and are related to soil texture and nutrient content. Three earthworm endogeic species were recorded in this study, with the exotic Pontoscolex corethrurus as the dominant species. We conclude that tropical endogeic earthworms may be potentially useful in ecotoxicological and biostimulation studies, and may have more ecological relevance than using epigeic earthworms. Further studies are needed to elucidate the hypotheses.
