CoNISMa, Consorzio Nazionale Interuniversitario per le Scienze del Mare, 00196 Roma, Italy; Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, 73100 Lecce, Italy.
Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, 73100 Lecce, Italy; CIRCMSB, Consorzio Interuniversitario di Ricerca in Chimica dei Metalli nei Sistemi Biologici, 70121 Bari, Italy.
Sci Total Environ. 2018 May 15;624:1455-1466. doi: 10.1016/j.scitotenv.2017.12.106. Epub 2017 Dec 27.
In invertebrate biomonitors of chemical pollution, emphasis has been generally given to mean accumulation patterns and how they reflect varying environmental levels of contamination. Intra-population variability, and how it relates with individual phenotypic traits, has received less attention. Here, a set of analytes including trace elements (B, Ba, Cd, Cr, Cu, Fe, Li, Mn, Ni, Pb, Sr, V, and Zn), macroelements (C, Ca, K, Mg, N, Na), and carbon and nitrogen stable isotopes (δC and δN) was measured in two populations of the crayfish Procambarus clarkii from Lake Trasimeno and Lake Bolsena (Central Italy). The influence of location, sex, body size, and condition factor was assessed; in addition, the analyte correlation profiles of the two populations were compared to verify their congruence. In general, significant inter-lake differences were observed in the concentration of both trace- and macroelements in crayfish tissues, generally mirroring the local chemistry of water and of benthic non-living matrices (sediment and plant detritus). Crayfish CN isotopic signatures excluded the occurrence of inter-lake variations in their omnivorous trophic habits. Correlation profiles varied considerably between the two populations in the nature and strength of bivariate relationships. However, Mantel tests and procrustean analyses indicated a general, significant congruence; C, N, and, to a lesser extent K, Li, Ni, Pb, and δC showed the highest procrustean residuals, suggesting that their associations with other analytes may be partially influenced by inter-population differences in growing phases. Our study indicates that the local geochemistry of the lacustrine environment influences the elemental fingerprint of Procambarus clarkii; the considerable inter-individual variability in the concentration of analytes, however, does not significantly reflect on their association, thus corroborating its effectiveness as an indicator species.
在化学污染的无脊椎动物生物监测中，重点通常放在平均积累模式上，以及它们如何反映不同的环境污染水平。种群内的变异性，以及它与个体表型特征的关系，受到的关注较少。在这里，我们在来自Trasimeno 湖和 Bolsena 湖（意大利中部）的两种克氏原螯虾种群中测量了包括微量元素（硼、钡、镉、铬、铜、铁、锂、锰、镍、铅、锶、钒和锌）、常量元素（碳、钙、钾、镁、氮、钠）以及碳和氮稳定同位素（δC 和 δN）在内的一组分析物。评估了位置、性别、体型和条件因素的影响；此外，还比较了这两个种群的分析物相关谱，以验证它们的一致性。一般来说，在螯虾组织中痕量和常量元素的浓度上，都观察到了湖泊之间的显著差异，这通常反映了水和底栖无生命基质（沉积物和植物碎屑）的当地化学性质。螯虾的 CN 同位素特征排除了其杂食性食性在湖泊之间存在差异的可能性。在两个种群之间，双变量关系的性质和强度的相关谱差异很大。然而，Mantel 检验和普罗克鲁斯分析表明存在一般的、显著的一致性；C、N 以及在较小程度上 K、Li、Ni、Pb 和 δC 表现出最高的普罗克鲁斯残差，表明它们与其他分析物的关联可能部分受到生长阶段种群间差异的影响。我们的研究表明，湖泊环境的地球化学性质影响了 Procambarus clarkii 的元素指纹；然而，分析物浓度的个体间差异很大，但它们之间的关联并没有显著反映出来，这证实了它作为指示物种的有效性。
