DEFORMATION OF THE ACTIVE SPACE IN THE LOW REYNOLDS-NUMBER FEEDING CURRENT OF CALANOID COPEPODS
DEFORMATION OF THE ACTIVE SPACE IN THE LOW REYNOLDS-NUMBER FEEDING CURRENT OF CALANOID COPEPODS
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DOI：
10.1139/f83-147
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发表时间：
1983-01-01
影响因子：
2.4
通讯作者：
ANDREWS, JC
中科院分区：
文献类型：
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作者：
ANDREWS, JC
活跃空间是藻类周围的区域，其中化学渗出物足够集中，以促进食草桡足类的行为反应。通过桡足类摄食流中的平流对藻类化学扩散影响的数值模型研究了桡足类对藻类的化学感应感知。最近对藻类和桡足类动物之间相遇的观察定义了双剪切、低雷诺数流的长度和速度尺度。这些尺度和剪切力被纳入馈电电流的分析描述中。化学物质在横向剪切流中的平流改变了渗出物的分布，从而产生了变形的活性空间。初始球形活动空间被拉长，并且活动空间的边缘在流动方向上比未受干扰的半径投影得更远一个数量级。桡足类收到的关于藻类逼近的预警是活动空间半径、检测阈值、藻类在流场中的位置以及渗出物的分子扩散率的函数。检测距离为 100 μm 时，半径、检测阈值和扩散率之间关系的示例表明，该模型对于广泛变化的参数值表现良好，并且松散地定义了控制参数的一些界限。
The active space is the zone around an alga where chemical exudates are sufficiently concentrated to promote a behavioral response in a grazing copepod. Chemosensory perception of algae by copepods is investigated with a numerical model of the effects of advection in copepod feeding currents on the chemical diffusing from algae. Recent observations of encounters between algae and calanoid copepods define length and speed scales for a doubly sheared, low Reynolds number flow. These scales and shears are incorporated in an analytical description of the feeding current. Advection of the chemical in the laterally sheared flow changes the distribution of the exudates to create a deformed active space. An initially spherical active space is elongated and the edge of the active space is projected an order of magnitude further in the direction of the flow than the undisturbed radius. The advance warning received by a copepod of an approaching alga is a function of the radius of the active space, the detection threshold, the position of the alga in the stream field, and the molecular diffusivity of the exudate. An example of the relation between radius, detection threshold and diffusivity for a detection distance of 100 .mu.m demonstrates that the model is well behaved for widely varying parameter values and loosely defines some bounds for the controlling parameters.