Quantifying maternal transfer of trace elements and stable isotopes in the endangered pelagic thresher shark (Alopias pelagicus).
Quantifying maternal transfer of trace elements and stable isotopes in the endangered pelagic thresher shark (Alopias pelagicus).
复制标题
量化濒临灭绝的远洋长尾鲨（Alopias pelagicus）中微量元素和稳定同位素的母体转移。
DOI：
10.2139/ssrn.4048724
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发表时间：
2022
期刊：
影响因子：
8.8
通讯作者：
Yunkai Li
中科院分区：
文献类型：
--
作者：
Zezheng Li;N. Hussey;Yunkai Li
为了量化母体在远洋长尾鲨（Alopias pelagicus）中提供的营养物质及其潜在的负面影响，研究人员分析了10只怀孕雌性和18个相关胚胎肌肉和肝脏中微量元素（必需元素：Co、Cr、Cu、Mn、Ni、Se和Zn；非必需元素：As、Ba、Cd、Hg和Pb）的浓度和稳定同位素（13C和15N）的分异。除锌和镍在肝脏中外，必需微量元素在胚胎中以较高的浓度卸载，而非必需微量元素在母胚组织中分布不均匀。观察到的汞浓度处于有毒水平，但所有胚胎组织中的Se: Hg摩尔比均大于1。所有元素在母体组织中的转移率与浓度呈负相关，表明黄鳝母体卵巢中存在调控机制。与母体相比，相关胚胎的肌肉和肝脏组织的δ13C和δ15N值较高。δ13C、δ15N和Δδ13C值与胚胎肌肉组织的前掌长度呈负相关，这可能反映了怀孕雌性在妊娠后期饮食-栖息地的变化，或者是生理变化改变了分娩期。较高浓度的必需元素与胚胎早期发育的潜在益处有关，汞水平表明一定程度的人为影响，后果未知，而同位素分离的方向性可能表明潜在的生殖迁移作为生育的保护机制。
To quantify maternal provisioning of nutrients in the pelagic thresher shark (Alopias pelagicus) and the potential for negative impacts, the concentrations of trace elements (essential: Co, Cr, Cu, Mn, Ni, Se, and Zn; nonessential: As, Ba, Cd, Hg, and Pb) and fractionation of stable isotopes (13C and 15N) were analyzed in the muscle and liver of 10 pregnant females and 18 associated embryos. Essential trace elements were observed to be offloaded at higher concentrations to embryos, with the exception of Zn and Ni in liver, while nonessential trace elements were unevenly distributed between maternal-embryo tissues. Observed Hg concentrations were at levels considered toxic in A. pelagicus, but the Se: Hg molar ratios in all embryonic tissues were all greater than one. A negative correlation was observed between transfer ratios and concentrations of all elements in maternal tissue, indicating the existence of a regulatory mechanism in maternal ovaries of A. pelagicus. Compared with maternal specimens, associated embryos had higher δ13C and δ15N values in muscle and liver tissue. Negative correlations were observed between δ13C, δ15N, and Δδ13C values and precaudal length in embryonic muscle tissue potentially reflecting either a dietary-habitat shift in pregnant females during the latter period of gestation or a physiological change modifying fractionation. Higher concentrations of essential elements are linked to potential benefits for embryos during early development, levels of Hg suggested a degree of anthropogenic impact with unknown consequences while the directionality of isotopic fractionation could suggest a potential reproductive migration as a protective mechanism for birthing.