摘要：Hydrocarbon contamination is known to reduce the soil microfauna, but little is known about the sensibility of endogeic earthworms towards it. The aim of this study was to investigate how the earthworm biomass and abundance was affected by a petroleum contamination. Endogeic earthworms were studied in an anthrosol soil contaminated with hydrocarbons after an oil spill in Cinco Presidentes (Tabasco, Mexico) 20 years ago. Monoliths of 0.5x0.5x0.4 m were taken along a transect at 10, 20, 40 and 80 m from the origin of the oil spill . Each monolith was divided in four layers (0-0.1, 0.1-0.2, 0.2-0.3 and 0.3-0.4 m) and the number of earthworms, soil characteristics and the concentration of polycyclic aromatic hydrocarbons (phenanthrene, anthracene and benzo(a)pyrene (BaP) were determined. BaP was detected, while anthracene and phenanthrene were not found. On average, the total abundance of the earthworms was 319 individuals m-2 with an average biomass of 43 g m-2, but their abundance was not correlated with the presence of BaP. Three different species of earthworms were detected with Pontoscolex corethrurus , an endogeic earthworm, the most abundant (75%). Based on the results obtained, the presence of P. corethrurus in the contaminated site indicated its tolerance towards BaP and its possible use in the remediation of hydrocarbon contaminated soils.
