测定持续生长的生物结构如耳石中的微量元素浓度,胡须,牙齿可以为生理和个体发育过程提供重要的见解。我们检查了11种微量元素的浓度(Li,Mg,Mn,Cu,Zn,Se,Rb,Sr,Cs,Ba,Pb)在66个加拿大东部北极白鲸(Delphinapterusleuas)的牙齿的年度牙本质生长层组(GLGs)中。这些微量元素中的一些在生命早期显示出清晰一致的模式,尽管女性或男性的微量元素数据中几乎没有长期趋势或信号。胎儿牙本质中Sr和Ba浓度的大变化反映在发育中的白鲸牙齿中元素沉积的子宫变化中。在出生后的头几年中,这些元素的显着变化可能与护理和随后的断奶有关。Mg,Mn,和锌在早期生命中也显示出清晰一致的模式,与牙本质稳定氮同位素(δ15N)数据密切相关,提示这些元素值得进一步研究,作为研究护理和断奶的潜在工具。Zn和Pb的沉积模式,与太平洋雌性海象(Odobenusrosmarusdivergens)的性成熟有关,白鲸牙齿不一致。一些个体(包括雄性)显示出与雌性海象中观察到的图案非常相似,而许多动物没有,也许是因为他们还没有达到性成熟。生命最初几年后,微量元素沉积缺乏清晰的模式可能是由于汇集了二十多年来收集的多个种群/地区的样本。但也可能表明元素浓度主要是由其他因素驱动的,生命后期的外在过程,并可能用作环境要素浓度的生物监测者或描绘种群结构的工具。
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 (δ15N) 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.