Institute of Marine Biology, National Taiwan Ocean University, Keelung, Taiwan.
Dept. of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, Taiwan.
PLoS One. 2018 Apr 23;13(4):e0196222. doi: 10.1371/journal.pone.0196222. eCollection 2018.
Trace metal dynamics have not been studied with respect to growth increments in octocorals. It is particularly unknown whether ontogenetic compartmentalization of trace metal accumulation is species-specific. We studied here for the first time the intracolonial distribution and concentrations of 18 trace metals in the octocorals Subergorgia suberosa, Echinogorgia complexa and E. reticulata that were retrieved from the northern coast of Taiwan. Levels of trace metals were considerably elevated in corals collected at these particular coral habitats as a result of diverse anthropogenic inputs. There was a significant difference in the concentration of metals among octocorals except for Sn. Both species of Echinogorgia contained significantly higher concentrations of Cu, Zn and Al than Subergorgia suberosa. We used for the first time exponential growth curves that describe an age-specific relationship of octocoral trace metal concentrations of Cu, Zn, Cd, Cr and Pb where the distance from the grip point was reflecting younger age as linear regressions. The larger colony (C7) had a lower accumulation rate constant than the smaller one (C6) for Cu, Zn, Cd, Cr and Pb, while other trace metals showed an opposite trend. The Cu concentration declined exponentially from the grip point, whereas the concentrations of Zn, Cd, Cr and Pb increased exponentially. In S. suberosa and E. reticulata, Zn occurred primarily in coenosarc tissues and Zn concentrations increased with distance from the grip point in both skeletal and coenosarc tissues. Metals which appeared at high concentrations (e.g. Ca, Zn and Fe) generally tended to accumulate in the outer coenosarc tissues, while metals with low concentrations (e.g. V) tended to accumulate in the soft tissues of the inner skeleton.
尚未针对珊瑚的生长增量研究痕量金属动态。特别是，痕量金属积累的个体发生区隔是否具有物种特异性尚不清楚。我们首次研究了从台湾北部海岸采集的柳珊瑚、复杂海鸡冠珊瑚和网状海鸡冠珊瑚的 18 种痕量金属在珊瑚内部的分布和浓度。由于各种人为输入，在这些特殊珊瑚栖息地采集的珊瑚中，痕量金属的水平大大升高。除了 Sn 以外，珊瑚中的金属浓度存在显著差异。两种海鸡冠珊瑚的 Cu、Zn 和 Al 浓度均明显高于柳珊瑚。我们首次使用指数生长曲线来描述柳珊瑚痕量金属 Cu、Zn、Cd、Cr 和 Pb 浓度的年龄特异性关系，其中从握持点到线性回归的距离反映了较年轻的年龄。较大的群体（C7）的 Cu、Zn、Cd、Cr 和 Pb 积累率常数低于较小的群体（C6），而其他痕量金属则表现出相反的趋势。Cu 浓度从握持点呈指数下降，而 Zn、Cd、Cr 和 Pb 的浓度则呈指数增加。在柳珊瑚和网状海鸡冠珊瑚中，Zn 主要存在于共肉组织中，并且 Zn 浓度随着与握持点的距离增加而增加，这发生在骨骼和共肉组织中。高浓度出现的金属（例如 Ca、Zn 和 Fe）通常倾向于在外部共肉组织中积累，而低浓度的金属（例如 V）则倾向于在内部骨骼的软组织中积累。
