Biological and environmental rhythms reflected in molluscan shell growth
Biological and environmental rhythms reflected in molluscan shell growth
复制标题
软体动物壳生长反映的生物和环境节律
DOI：
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发表时间：
1968
影响因子：
1.4
通讯作者：
C. Macclintock
中科院分区：
文献类型：
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作者：
G. Pannella;C. Macclintock
潮汐循环反映在许多近代和化石软体动物的壳的日常生长-增长序列中。在麻萨诸塞州的巴恩斯特布尔港，将双壳类的活标本在其生长边缘上刻槽，并在潮间带种植。在播种后间隔368天和723天捕杀的两批贝壳显示出与从切口到捕杀的天数相同的小生长增量。在日生长记录上叠加了冬季（薄日增量）和潮汐（厚日增量和薄日增量的14天周期）的影响。将Barnstable潮汐记录与第一年的增长进行比较可以发现，在每14天周期中，小潮时的日增量较小，大潮时的日增量较大。虽然潮汐模式存在于潮下雇佣兵壳中，但它们很少像潮间带壳那样明显。产卵模式不同于冬季模式；它们在壳中通过常规沉积的中断来表达，随后是一系列薄的每日增量。连续的双日模式序列，一个较厚的日增量之后是一个相对较薄的日增量，在M.雇佣兵中很常见。双壳动物鳞砗磲（Tridacna squamosa）的14天沉积周期最为明显。每个日小潮增量是一个简单的层，由一个暗区和一个亮区组成。每天的大潮增量是一个复杂的层，由两个明暗交替组成，由一个沉积断裂分开，这个沉积断裂比划分每天间隔的断裂更明显。化石生长-增量计数的初步结果表明，每个阴历月的平均日数总体上呈近代递减趋势。宾夕法尼亚的值是30.07±0.08，这个数字与Scrutton（1964）和Barker（1966）的数据大致一致，Scrutton每月在泥盆纪珊瑚上计算30.59天，Barker（1966）每月在宾夕法尼亚双壳类动物上计算30多天。
Tidal cycles are reflected in daily growth-increment sequences in shells of many Recent and fossil mollusks. Living specimens of the bivalve Mercenaria mercenaria were notched at the growing edge of the shell and planted intertidally in Barnstable Harbor, Massachusetts. Shells from two lots, killed at intervals of 368 and 723 days after planting, show the same number of small growth increments as there were days from notching to killing. Superimposed on daily growth record are effects of winter (thin daily increments) and tides (14-day cycles of thick and thin daily increments). Comparison of Barnstable tide record with the first year's growth shows that, for each 14-day cycle, thin daily increments form during neap tides and thicker daily increments form during spring tides. Although tidal patterns are present in subtidal Mercenaria shells, they are rarely as pronounced as in intertidal ones. Spawning patterns differ from winter patterns; they are expressed in the shell by an interruption of regular deposition followed by a series of thin daily increments. Continuous sequences of bidaily patterns, one thick daily increment followed by a relatively thin one, are common in M. mercenaria. The clearest 14-day cycles of deposition were seen in shells of the bivalve Tridacna squamosa. Each daily neap-tide increment is a simple layer consisting of a dark and light zone. Each daily spring-tide increment is a complex layer consisting of two light-dark alternations separated by a depositional break that is more pronounced than the breaks delimiting daily intervals. Preliminary results of growth-increment counts in fossils show a generally decreasing trend of the mean values of days per lunar month toward the Recent. The Pennsylvanian value is 30.07 ± 0.08, a figure that is in general agreement with those of Scrutton (1964), who counted 30.59 days per month on Devonian corals, and Barker (1966), who reported more than 30 days per month in Pennsylvanian bivalves.