Clark Casey T, Yang Panseok, Halden Norm, Ferguson Steven H, Matthews Cory J D
Washington Department of Fish & Wildlife, Olympia, WA, USA.
Department of Geological Sciences, University of Manitoba, Winnipeg MB, R3T 2N6, Canada.
Chemosphere. 2023 Nov;340:139938. doi: 10.1016/j.chemosphere.2023.139938. Epub 2023 Aug 25.
Determination of trace element concentrations in continuously growing biological structures such as otoliths, whiskers, and teeth can provide important insight into physiological and ontogenetic processes. We examined concentrations of 11 trace elements (Li, Mg, Mn, Cu, Zn, Se, Rb, Sr, Cs, Ba, Pb) in the annual dentine growth layer groups (GLGs) of teeth of 66 Eastern Canadian Arctic belugas (Delphinapterus leucas). Several of these trace elements displayed clear and consistent patterns in early life, though few longer term trends or signals were present in trace element data for either females or males. Large changes in Sr and Ba concentrations in fetal dentine reflected in utero shifts in element deposition in the teeth of developing belugas. Marked changes in these elements during the first years after birth were likely associated with the onset of nursing and subsequent weaning. Mg, Mn, and Zn also displayed clear and consistent patterns in early life that correlated strongly with dentine stable nitrogen isotope (δN) data, suggesting these elements merit further study as potential tools for studying nursing and weaning. Depositional patterns of Zn and Pb, which have been linked to sexual maturation in female Pacific walruses (Odobenus rosmarus divergens), were inconsistent in beluga teeth. Some individuals (including males) displayed patterns strongly resembling those observed in female walruses, whereas many animals did not, perhaps because they had not yet reached sexual maturity. The lack of clear patterns in trace element deposition after the first few years of life may have resulted from pooling samples from multiple populations/regions collected across more than two decades, but may also indicate that elemental concentrations are primarily driven by other, extrinsic processes later in life, and might be useful as biomonitors of environmental element concentrations or tools for delineating population structure.
确定不断生长的生物结构（如耳石、须和牙齿）中的微量元素浓度，可为生理和个体发育过程提供重要见解。我们检测了66头加拿大东部北极白鲸（白鲸属）牙齿年度牙本质生长层组（GLGs）中11种微量元素（锂、镁、锰、铜、锌、硒、铷、锶、铯、钡、铅）的浓度。这些微量元素中的几种在生命早期呈现出清晰且一致的模式，不过在雌性或雄性的微量元素数据中，长期趋势或信号较少。胎儿牙本质中锶和钡浓度的大幅变化反映了发育中的白鲸牙齿在子宫内元素沉积的变化。出生后最初几年这些元素的显著变化可能与哺乳开始及随后的断奶有关。镁、锰和锌在生命早期也呈现出清晰且一致的模式，与牙本质稳定氮同位素（δN）数据密切相关，这表明这些元素作为研究哺乳和断奶的潜在工具值得进一步研究。锌和铅的沉积模式与雌性太平洋海象（太平洋海象指名亚种）的性成熟有关，但在白鲸牙齿中并不一致。一些个体（包括雄性）呈现出与雌性海象中观察到的模式极为相似的情况，而许多动物则没有，这可能是因为它们尚未达到性成熟。生命最初几年后微量元素沉积缺乏清晰模式，可能是由于汇集了二十多年来从多个种群/地区采集的样本，但也可能表明生命后期元素浓度主要受其他外部过程驱动，并且可能作为环境元素浓度的生物监测指标或划分种群结构的工具。
