Ohnishi K, Takahashi A, Tanaka H, Ohnishi T
Department of Physiology, Nara Medical University, Japan.
Biol Sci Space. 1996 Dec;10(4):247-51. doi: 10.2187/bss.10.247.
The catfish Synodontis nigriventris shows a unique habit taking a stable upside-down posture in free water regardless of an above, one-sided illumination. This upside-down posture can be observed when the catfish is apart from objects because the catfish usually orients its ventral side towards the water bottom or objects due to a so-called ventral substrate response. Thus, it is not easy to study the mechanism of the upside-down posture. To resolve this problem, the frequency of the upside-down posture was measured by using various sizes of vessel in which the catfish was kept. Video analysis showed that the frequency of the upside-down posture depended on the space size around the catfish. The smaller the size became, the higher the frequency of the upside-down posture became. Furthermore, the frequency of the upside-down posture depended on the shape of the vessel bottom. Curved-bottom vessels induced the upside-down posture more frequently than flat bottom. These findings suggest that a small, curved-bottom vessel is ideal for researching the upside-down postural control mechanism.
鲶鱼黑腹歧须鮠表现出一种独特的习性，即在自由水中保持稳定的倒立姿势，无论上方是否有单侧光照。当鲶鱼远离物体时，可以观察到这种倒立姿势，因为鲶鱼通常会由于所谓的腹侧底物反应而将其腹侧朝向水底或物体。因此，研究倒立姿势的机制并不容易。为了解决这个问题，通过使用饲养鲶鱼的各种尺寸的容器来测量倒立姿势的频率。视频分析表明，倒立姿势的频率取决于鲶鱼周围的空间大小。尺寸越小，倒立姿势的频率越高。此外，倒立姿势的频率还取决于容器底部的形状。底部弯曲的容器比平底容器更频繁地诱发倒立姿势。这些发现表明，小的、底部弯曲的容器是研究倒立姿势控制机制的理想选择。
