Age- and size-based morphological comparison between the brown alga Sargassum macrocarpum (Heterokonta; Fucales) from different depths at an exposed coast in northern Kyoto, Japan
Age- and size-based morphological comparison between the brown alga Sargassum macrocarpum (Heterokonta; Fucales) from different depths at an exposed coast in northern Kyoto, Japan
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DOI：
10.1007/s10811-013-0002-y
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发表时间：
2013-12-01
影响因子：
3.3
通讯作者：
Takeno, Koji
中科院分区：
文献类型：
--
作者：
Endo, Hikaru;Nishigaki, Tomokazu;Takeno, Koji
虽然大的多年生褐藻是已知的，表现出很大的形态可塑性，响应特定的环境因素，如深度和波曝光，有很少的报告显示这种形态的变化，考虑到年龄或大小组成。在这里，我们进行了年龄和大小为基础的形态学比较多年生棕色马尾藻macrocarpum C。在日本北方京都裸露的海岸，Agardh从他们的深度上限，中间深度和深度下限。模型II回归拟合年龄或柄直径（SD）和形态变量，包括SD，固着重量（HW），主分枝数（MBN），总重量（MBW），主分枝，叶状体重量（TW），叶状体长度（TL）之间的关系，从每个深度区的30个季节性采集的标本。使用SMATR分析这些回归方程中的深度之间的差异。虽然SD，HW，和MBN的标本没有不同的深度下的年龄和SD的基础上，有显着差异的MBW，TW，和TL的深度之间，这表明TW的深度之间的差异是由于MBW的差异。而在许多月份，下限深度的TW低于上限深度或中间深度，在某些月份，上限深度的TL短于中间深度或下限深度。这些结果表明S.在较浅深度的大果往往具有短而浓密的形态，而在较深深度的大果具有长而不那么浓密的形态。
Although large perennial brown algae are known to show great morphological plasticity responding to specific environmental factors such as depth and wave exposure, there are few reports showing this morphological variability taking into account age or size composition. Here, we conducted age- and size-based morphological comparison between the perennial brown alga Sargassum macrocarpum C. Agardh from their upper depth limit, middle depth, and lower depth limit at an exposed coast in northern Kyoto, Japan. Model II regression was fitted for the relationships between age or stipe diameter (SD) and morphological variables including SD, holdfast weight (HW), number of main branches (MBN), total weight of main branches (MBW), thallus weight (TW), and thallus length (TL) of 30 specimens collected seasonally from each depth zone. The differences between depths in these regression equations were analyzed using SMATR. Although SD, HW, and MBN of the specimens did not differ between depths under both age- and SD-basis, there were significant differences between depths in MBW, TW, and TL, suggesting that the differences in TW between depths are resulted from differences in MBW. Whereas TW at the lower depth limit was lower than that at the upper depth limit or middle depth in many months, TL at the upper depth limit was shorter than that at the middle depth or lower depth limit in some months. These results suggest that S. macrocarpum at shallower depths tend to have short and bushy morphology, whereas those at deeper depths have long and less bushy morphology.