Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2011 Apr;197(4):321-7. doi: 10.1007/s00359-010-0615-4. Epub 2010 Dec 14.
Blind Mexican cave fish (Astyanax fasciatus) lack a functional visual system and have been shown to sense their environment using a technique called hydrodynamic imaging, whereby nearby objects are detected by sensing distortions in the flow field of water around the body using the mechanosensory lateral line. This species has also been noted to touch obstacles, mainly with the pectoral fins, apparently using this tactile information alongside hydrodynamic imaging to sense their surroundings. This study aimed to determine the relative contributions of hydrodynamic and tactile information during wall following behaviour in blind Mexican cave fish. A wall was custom built with a 'netted' region in its centre, which provided very similar tactile information to a solid tank wall, but was undetectable using hydrodynamic imaging. The fish swam significantly closer to and collided more frequently with the netted region of this wall than the solid regions, indicating that the fish did not perceive the netted region as a solid obstacle despite being able to feel it as such with their pectoral fins. We conclude that the touching of objects with the pectoral fins may be an artefact of the intrinsic link between pectoral fin extensions and tail beating whilst swimming, and does not function to gather information. During wall following, hydrodynamic information appears to be used strongly in preference to tactile information in this non-visual system.
盲眼墨西哥洞穴鱼（Astyanax fasciatus）缺乏功能性视觉系统，据观察，它们使用一种称为水动力成像的技术来感知周围环境，通过身体周围水流场的感应来检测附近的物体，这种感应是通过机械感受侧线完成的。这种物种还被注意到会触摸障碍物，主要是使用胸鳍，显然是将这种触觉信息与水动力成像一起用于感知周围环境。本研究旨在确定在盲眼墨西哥洞穴鱼的壁面跟随行为中，水动力和触觉信息的相对贡献。一个壁面是定制的，其中心有一个“网状”区域，该区域提供与实壁非常相似的触觉信息，但无法用水动力成像检测到。鱼在这个壁面的网状区域游得更近，碰撞的频率也更高，这表明尽管鱼可以用胸鳍感觉到，但它们并没有将网状区域视为固体障碍物。我们的结论是，用胸鳍触摸物体可能是胸鳍延伸和游泳时尾鳍拍打之间内在联系的一个特征，而不是用于收集信息。在壁面跟随过程中，在这个非视觉系统中，水动力信息似乎比触觉信息更被强烈地优先使用。
