Role of lipids in the maintenance of neutral buoyancy by zooplankton
Role of lipids in the maintenance of neutral buoyancy by zooplankton
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DOI：
10.3354/meps263093
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发表时间：
2003-01-01
影响因子：
2.5
通讯作者：
Dower, JF
中科院分区：
文献类型：
--
作者：
Campbell, RW;Dower, JF
许多类型的浮游动物含有大量的脂质。通常，这些脂质代表能量储存化合物，但也有人认为脂质在浮力调节中发挥作用。脂质被认为决定了大型桡足类动物的越冬深度，并且人们普遍认为这些生物体在某个“中性浮力深度”越冬。然而，脂质通常比海水更容易压缩，并且具有更大的热膨胀性。这意味着任何深度的中性浮力本质上都是不稳定的。模型结果表明，这种不稳定性导致的上升速率在深度（温度变化很小）很小，这表明动物在越冬时保持在深度的简单方法。然而，模型结果还表明，桡足类（或任何小型浮游生物）的浮力特性对其相对生化成分极其敏感。这给维持垂直位置带来了问题，但对于垂直迁移也可能有用。
Many types of zooplankton contain large proportions of lipids. Usually, these lipids represent energy storage compounds, but it has also been suggested that lipids play a role in buoyancy regulation. Lipids are thought to determine the overwintering depth of large calanoid copepods, and it has been widely assumed that these organisms overwinter at some 'depth of neutral buoyancy'. However, lipids are generally more compressible, and have a larger thermal expansion than seawater. This means that any depth of neutral buoyancy will be inherently unstable. Model results show that the ascent rates attributable to this instability are small at depth (where temperature changes are small), suggesting a simple way for animals to remain at depth while overwintering. However, model results also show that the buoyant properties of a copepod (or any small plankter) are extremely sensitive to its relative biochemical composition. This presents problems to maintaining vertical position, but may also be useful for vertical migrations.