Department of Sciences, University Roma Tre, Viale Guglielmo Marconi 446, Rome, 00146, Italy.
Institute for Research on Pain, ISAL-Foundation, Via San Salvador 204, Rimini, Torre Pedrera, 47922, Italy.
Ecotoxicology. 2017 Apr;26(3):396-404. doi: 10.1007/s10646-017-1772-9. Epub 2017 Feb 10.
Investigations on asymmetries showed that deviations from perfect bilateral symmetry are interpreted as environmental changes inducing developmental instability. Since morphological abnormalities increase with pollution, deformations may be considered indicators of the organism exposition to pollution. Therefore, the onset of asymmetry in otherwise normally symmetrical traits has been used as a measure of some stresses as well. In this context, we studied how marine pollution affects the valve morphological alterations in the mussel Mytilus galloprovincialis. We used 180 specimens (30 per site) from the aquaculture area of Goro (River Po delta, northern Adriatic Sea), translocated, and released within 50 × 50 × 50 cm cages in five sites: two disturbed and one undisturbed near Naples (eastern Tyrrhenian Sea), and one disturbed and one undisturbed near Siracusa (western Ionian Sea). Disturbed sites were stressed by heavy industrialization and heavy tankers traffic of crude and refined oil, and were defined basing on sediment contamination. In particular, by the cone-beam computed tomography we obtained 3D virtual valve surfaces to be analyzed by the geometric morphometric techniques. Specifically, we focused the levels of the shell shape fluctuating asymmetry in relation to the degrees of marine pollution in different sites of the Tyrrhenian Sea. The Mahalanobis distances (interpreted as proxy of the individual shape asymmetry deviation from the mean asymmetry) significantly regressed with the sediment contamination gradient. Indeed, although the left-right differences were normally distributed in each studied site, the individual asymmetry scores (IAS) significantly varied amongst the investigated sites. IAS showed higher values in disturbed areas than those of undisturbed ones in both Tyrrhenian and Ionian Sea. Our results are consistent with past studies on molluscans and other taxa, demonstrating some detrimental effects of chemicals on organisms, although the investigated morphological marker did not discriminate the real disturbance source. Our findings indicate that the mussels act as a prognostic tool for sea pollution levels driving detrimental effects on benthic community.
研究不对称性表明，偏离完美的双侧对称性被解释为环境变化导致发育不稳定。由于形态异常随着污染的增加而增加，因此变形可以被认为是生物体暴露于污染的指标。因此，通常对称特征的不对称性的出现已被用作某些压力的衡量标准。在这种情况下，我们研究了海洋污染如何影响贻贝 Mytilus galloprovincialis 的瓣形态变化。我们使用了来自 Gor 的水产养殖区的 180 个标本（每个地点 30 个）（波河三角洲，亚得里亚海北部），在五个地点转移并释放了 50×50×50cm 的笼子：那不勒斯附近的两个受干扰和一个未受干扰的地点（东第勒尼安海），以及锡拉库扎附近的一个受干扰和一个未受干扰的地点（西爱奥尼亚海）。受干扰的地点受到重工业和原油和精炼油的大型油轮运输的压力，并根据沉积物污染进行了定义。特别是，我们通过锥束计算机断层扫描获得了 3D 虚拟瓣表面，并用几何形态测量技术进行分析。具体来说，我们关注了与不同地点的海洋污染程度有关的壳形状波动不对称的水平。马哈拉诺比斯距离（解释为个体形状不对称度与平均不对称度的偏差的代理）与沉积物污染梯度显著回归。事实上，尽管在每个研究地点，左右差异都呈正态分布，但个体不对称分数（IAS）在调查地点之间存在显著差异。IAS 在受干扰的地区明显高于未受干扰的地区，无论是在第勒尼安海还是爱奥尼亚海。我们的结果与过去对软体动物和其他分类群的研究一致，证明了化学物质对生物体的一些有害影响，尽管所研究的形态标记物不能区分真正的干扰源。我们的研究结果表明，贻贝是海洋污染水平的预测工具，对底栖群落有不利影响。
