Depth distributions determined with SCUBA, and associated studies of the freshwater unionid clams Elliptio complanata and Anodonta grandis in Lake Bernard, Ontario
Depth distributions determined with SCUBA, and associated studies of the freshwater unionid clams Elliptio complanata and Anodonta grandis in Lake Bernard, Ontario
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通过水肺潜水确定的深度分布，以及对安大略湖伯纳德湖的淡水蛤蜊 Elptio complanata 和 Anodonta grandis 的相关研究
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发表时间：
1978
期刊：
影响因子：
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通讯作者：
L. Johnson
中科院分区：
文献类型：
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作者：
A. Ghent;R. Singer;L. Johnson
水下圆区采样显示，Elliptio complanata 仅限于坚硬的沙子、波浪席卷的浅滩，该物种的重壳和狭窄的腹角使其能够在浅滩上立足。 E. complanata 种群位于海岸 4 米处，大部分位于 2.5 米或更深处。 Anodonta grandis种群向岸边的低密度延伸与E. complanata重叠，但Anodonta grandis种群向湖延伸至13-14米的深度，其轻质的外壳和宽阔的腹角使其能够栖息在柔软、松散的淤泥基质上。伯纳德湖中 6 米或更深的深度积累了 10 厘米或以上的这种软基质覆盖层，超出了表面波的干扰。从这些更深处采集的样本明显发育迟缓，但这种发育迟缓被证明是一种渐进现象，随着深度的增加而增加，而不是在任何特定深度突然出现阈值效应。苋菜身长、身高、肥胖、体重之间的回归关系
Underwater circular-plot sampling showed Elliptio complanata to be confined to the hard-sand, wave-swept shallows, on which the heavy shell and narrow ventral angle of this species permit it to retain a footing. The E. complanata population lay shoreward of 4 m, mostly at depths of 2.5 m or less. A shoreward, low-density extension of the Anodonta grandis population overlaps that of E. complanata, but the A. grandis population extends lakeward to depths of 13–14 m, where its lightweight shell and wide ventral angle permit it to sit on the soft, unconsolidated silt substrate. A blanket of 10 cm or more of this soft substrate has accumulated in Lake Bernard at depths of 6 m or more, beyond the disturbance of surface waves. Specimens taken from these greater depths were markedly stunted, but such stunting was shown to be a progressive phenomenon, increasing with greater depth, rather than a sudden threshold effect at any particular depth. Regression relations among length, height, obesity, and weight of A. gr...