The flow fields involved in hydrodynamic imaging by blind Mexican cave fish (Astyanax fasciatus). Part I: open water and heading towards a wall
The flow fields involved in hydrodynamic imaging by blind Mexican cave fish (Astyanax fasciatus). Part I: open water and heading towards a wall
复制标题
DOI：
10.1242/jeb.040741
复制
发表时间：
2010-11
影响因子：
2.8
通讯作者：
S. Windsor;Stuart Norris;S. Cameron;G. Mallinson;J. Montgomery
中科院分区：
文献类型：
--
作者：
S. Windsor;Stuart Norris;S. Cameron;G. Mallinson;J. Montgomery
盲墨西哥洞穴鱼（Astyanax fasciatus）通过感知身体周围水流的变化来感知附近物体的存在。利用这种流体动力学成像能力，鱼可以获得的信息取决于它在滑行时产生的流场的特性，以及物体的存在如何改变流场。在这里，我们使用粒子图像测速技术来测量周围的流场滑翔盲洞鱼，因为他们通过开放的水域移动时，走向墙壁。这些测量，结合计算流体动力学模型，被用来估计刺激的侧线系统的鱼。我们的研究结果表明，有一个高压区周围的鼻子的鱼，低压区对应于加速流周围最宽的部分的身体和厚层流边界层的身体。当正面接近墙壁时，刺激侧线的变化仅限于身体的前20%。假设鱼对侧线刺激的某种相对变化很敏感，发现在较高雷诺数下游泳会略微降低鱼在迎面接近时可以检测到墙壁的距离，这与先前预期的相反。然而，当考虑到环境噪声的影响时，以较高的速度游泳可能会提高刺激对侧线的信噪比。
SUMMARY Blind Mexican cave fish (Astyanax fasciatus) sense the presence of nearby objects by sensing changes in the water flow around their body. The information available to the fish using this hydrodynamic imaging ability depends on the properties of the flow field it generates while gliding and how this flow field is altered by the presence of objects. Here, we used particle image velocimetry to measure the flow fields around gliding blind cave fish as they moved through open water and when heading towards a wall. These measurements, combined with computational fluid dynamics models, were used to estimate the stimulus to the lateral line system of the fish. Our results showed that there was a high-pressure region around the nose of the fish, low-pressure regions corresponding to accelerated flow around the widest part of the body and a thick laminar boundary layer down the body. When approaching a wall head-on, the changes in the stimulus to the lateral line were confined to approximately the first 20% of the body. Assuming that the fish are sensitive to a certain relative change in lateral line stimuli, it was found that swimming at higher Reynolds numbers slightly decreased the distance at which the fish could detect a wall when approaching head-on, which is the opposite to what has previously been expected. However, when the effects of environmental noise are considered, swimming at higher speed may improve the signal to noise ratio of the stimulus to the lateral line.