Meiobenthic nematodes have been designated as sensitive global models in the development of biomonitoring and ecotoxicology monitoring programs howbeit the sensitivity of these organisms against oxidative stress biomarkers have never been addressed. The present study aimed to decipher this research axis after selecting and culturing a single nematode species from an entire community through original laboratory protocols. The purpose of this investigation was to change the grain size of the sediment into the immediate environment of nematodes by progressively adding a biosubstrate made from Sepia officinalis endoskeletton. At the end of the experiment, Metoncholaimus pristiurus became the unique component of the nematode species when the sediment was enriched with 80% of S. officinalis powder. After the mono-species level had been achieved, the selected species was fed on an another biosubstrate made from bodies of Porcellio scaber under the identical laboratory controlled conditions of light and temperature adopted during the selection process. Accordingly, the bioassay protocol this study layed new foundations for the study of meiobenthic nematodes in the biomarker field. Our results revealed that, in case of M. pritiurus, discernible oxidative stress responses are valid for catalase and gluthatione S-transferase. Indeed, for both enzymes, a clear increase in the activity was recorded, and the response was more reinforced when zinc and permethrin were administrated in combination. The relevance of the protocols proposed in this work parallels their global applicability to reach and maintain the monospecific level in laboratory by using biosubstrates made from animals widely distributed. It is true also that our data provided the first results in terms of biochemical biomarkers for meiobenthic nematodes and showed that the selected taxa, M. pristiurus, could be one of the first marine taxa responding early to the tested stressors, zinc and permethrin, even at very low concentrations.

中文翻译：

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选育新的Metoncholaimus pristiurus的新方案，并对中底线虫的氧化应激生物标记物进行首次评估。

尽管从未解决过这些生物对氧化应激生物标志物的敏感性，但在生物监测和生态毒理学监测计划的开发中，已将减灭性线虫定为敏感的全球模型。本研究旨在通过原始实验室规程从整个社区中选择和培养单个线虫物种后，以此为研究方向。这项研究的目的是通过逐渐添加由棕褐色内生骨骼制成的生物底物，将沉积物的粒径改变为线虫的直接环境。在实验结束时，当沉积物中富含80％的厚朴链霉菌粉时，猪齿肠菌成为线虫物种的独特成分。在达到单物种水平之后，在选择过程中采用的相同实验室控制的光和温度条件下，将选定的物种饲喂另一种由Porcellio scaber体制成的生物底物上。因此，本研究的生物测定规程为生物标志物领域的中底线虫的研究奠定了新的基础。我们的研究结果表明，在M. pritiurus的情况下，可辨别的氧化应激反应对过氧化氢酶和谷胱甘肽S-转移酶有效。实际上，对于这两种酶，均记录到活性明显增加，并且当锌和苄氯菊酯组合施用时，反应更加增强。在这项工作中提出的协议的相关性与它们在全球的适用性平行，通过使用由分布广泛的动物制成的生物底物达到并保持实验室的单特异性水平。确实，我们的数据提供了关于中底线虫的生物化学生物标志物的第一个结果，并表明所选的类群，M。pristiurus，可能是最早对测试的应激源（锌和苄氯菊酯）做出反应的首批海洋类群之一，甚至在非常低的浓度。