Laboratory of Applied Ichthyology, Vila Velha University, Av. Comissário José Dantas de Melo, 21, Boa Vista, 29102-770, Vila Velha, ES, Brazil.
Laboratory of Health and Wildlife, Vila Velha University, Av. Comissário José Dantas de Melo, 21, Boa Vista, 29102-770, Vila Velha, ES, Brazil.
Ecotoxicology. 2021 May;30(4):643-657. doi: 10.1007/s10646-021-02384-8. Epub 2021 Mar 22.
The aim of this study was to assess whether possible metal contamination in the sediment of the nests of giant Amazon river turtle, Podocnemis expansa, could contaminate eggs and hatchlings, triggering genotoxic damage. Therefore, sediments of P. expansa nests from two sites in the Brazilian Amazon were evaluated, with the first being collected at Araguaia River and the second at Crixás-Açu River. Newly hatched offspring, eggs, and sediments were collected from the beaches of these two rivers and the quantification of metals (Al, Cd, Co, Cr, Cu, Fe, Mn, Pb, and Zn) was carried out by atomic absorption spectroscopy. All targeted metals were found in both sediment and P. expansa biological samples collected on the beaches presenting higher concentrations in the sediment of Crixás-Açu River. Metals found in the eggshells before nesting and in the egg contents were maternally transferred. Moreover, augmented concentration of metals led by metal transfer from the nests sediments were detected in the eggshells after nesting (ENH) and in the newly hatched offspring (H). Probably this metal relocation to the newly hatchlings augmented the frequency of micronuclei in their blood, presenting 15.25‰ in hatchling found in Crixás-Açu River beaches and 10‰ in newly hatched animals from Araguaia River beaches. These results indicate the occurrence of maternal transfer of metals (essential or not) to the eggs in testudines as well as a transference from the sediments to the nesting eggs, triggering genotoxic effects on the hatchlings.
本研究旨在评估巨型亚马逊河龟（Podocnemis expansa）巢中的沉积物中是否存在可能的金属污染，从而污染卵和孵化幼体，引发遗传毒性损伤。因此，评估了来自巴西亚马逊地区两个地点的 P. expansa 巢的沉积物，第一个地点位于 Araguaia 河，第二个地点位于 Crixás-Açu 河。从这两条河的海滩上收集了刚孵化的后代、卵和沉积物，并通过原子吸收光谱法对金属（Al、Cd、Co、Cr、Cu、Fe、Mn、Pb 和 Zn）进行定量分析。所有目标金属都在来自这两个地点的海滩上采集的沉积物和 P. expansa 生物样本中被发现，其中 Crixás-Açu 河的沉积物中浓度更高。在巢前和卵内容物中发现的金属是通过母体转移而来的。此外，还检测到由于来自巢沉积物的金属转移而导致的卵壳（ENH）和刚孵化的幼体（H）中金属浓度增加。这种金属向刚孵化幼体的重新分布可能增加了它们血液中的微核频率，在 Crixás-Açu 河海滩上发现的孵化幼体中为 15.25‰，在 Araguaia 河海滩上发现的刚孵化的动物中为 10‰。这些结果表明，在龟类中存在金属（必需或非必需）向卵的母体转移，以及从沉积物向巢卵的转移，从而对孵化幼体产生遗传毒性影响。
