Department of Biology, Laboratory of General Biology, College of Science, University of Ha'il, Ha'il, 81451, Saudi Arabia; Section of Histology-Cytology, Medicine Faculty of Tunis, University of Tunis El Manar, 1007 La Rabta, Tunis, Tunisia.
University of Carthage, Faculty of Sciences of Bizerte, Laboratory of Environment Biomonitoring, Coastal Ecology and Ecotoxicology Unit, 7021, Zarzouna, Tunisia.
Environ Pollut. 2023 Jan 1;316(Pt 1):120459. doi: 10.1016/j.envpol.2022.120459. Epub 2022 Oct 20.
Polycyclic aromatic hydrocarbons (PAHs) are toxic for humans and marine fauna alike. The current study assessed the impact of PAHs on the migratory behaviour of meiobenthic nematodes collected from the Bizerte lagoon, Tunisia. The experiment lasted for 15 days and was carried in open microcosms, which comprised a lower, contaminated and an upper, uncontaminated compartment. Three treatments were used, for each of them an untreated control was set up: sediment contaminated with chrysene (116 ng g dry weight (DW), with phenanthrene (116 ng g DW) and a mixture of both. The results showed a significant decrease in diversty and abundance in the lower, contaminated compartments compared to the upper zones. The results also highlighted that under an increased stress some species progressively increased in number, these were considered PAH-tolerant species such as Odontophora villoti, some others had an occasionally increased in number were considered as opportunistic species, such as Paracomesoma dubium and the species that showed a progressive decreased in number, such as Metoncholaimus pristiurus and Steineria sp., Terschellingia. longicaudata, and Oncholaimellus sp. were classified as PAH-sensitive. Moreover, an increase in the activity of biochemical biomarkers was observed following the exposure of males and gravid females of T. longicaudata to 29, 58 and 87 ng g DW of chrysene and phenanthrene paralleled by a higher vulnerability of the latter demographic category. Besides, a significant decrease in fertility of females and an increase in pharyngeal sucking power were observed for both types of PAHs considered. The sex ratio was also significantly imbalanced in the favor of males, which suggest that chrysene and phenanthrene affect also the hormone system of T. longicaudata. The high affinities of these PAHs and their molecular interactions with both germ line development protein 3 (GLD-3) and sex-determining protein (SDP) may justify these results and explain the toxicokinetic attributes.
多环芳烃 (PAHs) 对人类和海洋动物都具有毒性。本研究评估了 PAHs 对从突尼斯比塞大泻湖采集的小型底栖线虫洄游行为的影响。该实验持续了 15 天，在开放的微宇宙中进行，微宇宙由一个下部污染区和一个上部未污染区组成。使用了三种处理方法，每种方法都设置了一个未处理的对照：用 chrysene（116ng g 干重 (DW)）、phenanthrene（116ng g DW）和两者的混合物污染的沉积物。结果表明，与上部区域相比，下部污染区的多样性和丰度显著下降。结果还表明，在压力增加的情况下，一些物种的数量逐渐增加，这些物种被认为是 PAH 耐受物种，如 Odontophora villoti，还有一些物种的数量偶尔增加，被认为是机会主义物种，如 Paracomesoma dubium 和数量逐渐减少的物种，如 Metoncholaimus pristiurus 和 Steineria sp.，Terschellingia longicaudata 和 Oncholaimellus sp.。此外，暴露于 chrysene 和 phenanthrene 的 T. longicaudata 雄性和孕产雌性的生化生物标志物活性增加，同时后者的脆弱性增加，这表明它们对 PAH 更为敏感。此外，两种类型的 PAHs 都会导致雌性的繁殖力显著降低，咽吸力量增加。雌雄比例也明显失衡，偏向雄性，这表明 chrysene 和 phenanthrene 也会影响 T. longicaudata 的激素系统。这些 PAHs 的高亲和力及其与生殖系发育蛋白 3 (GLD-3) 和性别决定蛋白 (SDP) 的分子相互作用可能解释了这些结果和解释了毒性动力学特征。
