Species responses to stress are expected to be dependent on their life-history strategy. In this study, we compare the responses of two free-living marine nematodes, Litoditis marina and Diplolaimella dievengatensis, both considered opportunistic, fast-growing, and stress-tolerant species, to the exposure to sublethal concentrations of sodium dodecyl sulfate (SDS) surfactant. Specifically, we evaluated the growth and reproduction rates, as well as the survival of individuals exposed from eggs and/or juveniles (J1) onwards. Exposure to SDS significantly affected the growth and reproduction rates of both species. However, whereas growth and reproduction rates of D. dievengatensis were significantly enhanced at low and intermediate concentrations of SDS (0.001% and 0.003%), for L. marina both parameters were significantly reduced by all SDS concentrations tested (0.001%, 0.003% and 0.006%). Exposure to SDS did not affect the survival of adult nematodes of D. dievengatensis, while for L. marina, survival of males exposed to 0.006% SDS was significantly reduced compared to the control. Responses of the life-history traits growth, fecundity and survival did not exhibit clear trade-offs. The contrasting responses of D. dievengatensis and L. marina indicate that biologically and ecologically similar species can have remarkably distinct tolerances to stress, and that, in agreement with recent studies, rhabditid nematodes cannot a priori be considered very stress tolerant. Consequently, single species traits and phylogenetic relatedness are poor predictors of nematode responses to toxic stress posed by anthropogenic activities.

物种对压力的反应预计将取决于其生命史策略。在这项研究中，我们比较了两种自由生存的海洋线虫，滨海Litoditis marina和线虫Diplolaimella dievengatensis，它们被认为是机会性，快速生长和耐胁迫的物种，对暴露于致死浓度的十二烷基硫酸钠（SDS）表面​​活性剂的反应。具体而言，我们评估了从鸡蛋和/或幼鱼（J1）开始接触的个体的生长和繁殖率以及其存活率。接触SDS会显着影响两个物种的生长和繁殖速率。然而，D。dievengatensis的生长和繁殖率在低和中等浓度的SDS（0.001％和0.003％）下，L。marina显着增强，对于所有滨海链球菌，所有测试的SDS浓度（0.001％，0.003％和0.006％）均显着降低了两个参数。暴露于SDS不会影响Devengeatensis的成虫线虫的存活，而对于滨海李斯特菌，与对照组相比，暴露于0.006％SDS的雄性的存活显着降低。生活史特征的增长，繁殖力和生存的反应并没有表现出明显的权衡。的对比反应D. dievengatensis和L.码头这表明生物学和生态上相似的物种对压力具有明显不同的耐受性，并且与最近的研究一致，大戟线虫不能事先被认为是非常耐胁迫的。因此，单一物种的性状和系统发育的关联性是线虫对人为活动造成的毒性胁迫反应的不良预测指标。