Elevated heavy metal concentrations in soils are a cause for concern as they are hazardous to soil organisms including earthworms which are considered as ecosystem engineers. Current ecotoxicity tests predominantly use temperate earthworm species, and thus there is the need to include a broader genera of native species to improve ecological risk assessment. Alma nilotica, is a tropical anecic earthworm species that survives well under laboratory conditions and has potential for use in ecotoxicology testing but lacks published toxicity data for important pollutants. Growth and reproduction bioassays were carried out with A. nilotica to determine the relationship between the concentrations of Cu, Zn, Pb and Cr in spiked soils and their bioaccumulation and toxic effects. Positive linear relationships were found between soil-metal and internal earthworm-metal concentrations. Cu did not inhibit growth up to 35 days of exposure but became toxic with longer exposure duration. Zn was not regulated by A. nilotica although it is an essential metal that is well regulated by Eisenia sp. commonly used in standard ecotoxicity tests, showing differences in metal regulation by earthworms of different ecological categories. Based on bioaccumulation factors (BAFs), growth inhibition and reproduction effects the metals were ranked in decreasing toxicity as Pb > Cr > Zn > Cu. The mean 20% Internal Effects Concentrations (IEC20s) for reproduction were 1.04, 2.9, 8.3 and 224.2 mg metal kg⁻¹ earthworm for Pb, Cr, Zn and Cu respectively. These data can contribute to the improvement of metal risk assessment particularly in tropical contexts.

土壤中重金属浓度升高令人担忧，因为它们对土壤生物（包括被视为生态系统工程师的蚯蚓）有害。目前的生态毒性测试主要使用温带蚯蚓物种，因此需要包括更广泛的本地物种属以改进生态风险评估。Alma nilotica是一种热带厌氧蚯蚓物种，在实验室条件下生存良好，具有用于生态毒理学测试的潜力，但缺乏已发表的重要污染物的毒性数据。对尼罗罗非鱼进行生长和繁殖生物测定，以确定加标土壤中铜、锌、铅和铬的浓度与其生物富集和毒性作用之间的关系。土壤金属浓度和蚯蚓体内金属浓度之间存在正线性关系。Cu 在暴露长达 35 天的时间内不会抑制生长，但随着暴露时间的延长会变得有毒。锌不受尼罗河曲霉的调节，尽管它是一种必需金属，受到爱胜蚓的良好调节。常用于标准生态毒性测试，显示不同生态类别的蚯蚓对金属的调节差异。根据生物累积因子 (BAF)、生长抑制和繁殖效应，金属的毒性降低顺序为：Pb > Cr > Zn > Cu。Pb、Cr、Zn 和 Cu 的繁殖平均 20% 内部效应浓度 (IEC20s) 分别为 1.04、2.9、8.3 和 224.2 mg 金属 kg ^-1蚯蚓。这些数据有助于改进金属风险评估，特别是在热带地区。