Ohnishi K, Takahashi A, Koyama M, Ohnishi T
Department of Physiology, Nara Medical University, Japan.
Biol Sci Space. 1996 Dec;10(4):252-8. doi: 10.2187/bss.10.252.
The upside-down catfish Synodontis nigriventris has a unique habit of swimming and resting upside-down in free water. This behavior leads to the assumption that the catfish has a specific gravity information processing system. We examined the postural control behaviors in the catfish under clinorotation which is usually used for producing pseudo-microgravity. Synodontis nigriventris kept its body posture at a stable area of the rotated flask in which the catfish was kept, when it was clinorotated at the rate of 60 rpm. In contrast to Synodontis nigriventris, a related species, Corydoras paleatus, did not show such steady postural control. When the flask was rotated at a lower rate of 30 rpm or a higher rate of 100 rpm, Synodontis nigriventris as well as Corydoras paleatus showed a considerable disturbed control of body posture. In this condition, they were frequently rotated with the flask. These findings suggest that Synodontis nigriventris has a high ability to keep upside-down posture and the gravity sensation in this catfish is likely to contribute to its different postural control from that of many other fishes.
倒立鲶鱼（Synodontis nigriventris）具有在自由水体中倒立游泳和休息的独特习性。这种行为引发了一种假设，即鲶鱼拥有一个比重信息处理系统。我们研究了通常用于产生模拟微重力的clinorotation条件下鲶鱼的姿势控制行为。当以60转/分钟的速度进行clinorotation时，倒立鲶鱼在装有它的旋转烧瓶的稳定区域内保持身体姿势。与倒立鲶鱼不同，其近缘物种巴氏兵鲶（Corydoras paleatus）并未表现出这种稳定的姿势控制。当烧瓶以30转/分钟的较低速度或100转/分钟的较高速度旋转时，倒立鲶鱼和巴氏兵鲶都表现出对身体姿势的显著干扰控制。在这种情况下，它们经常随烧瓶一起旋转。这些发现表明，倒立鲶鱼具有很强的保持倒立姿势的能力，并且这种鲶鱼的重力感知可能有助于其与许多其他鱼类不同的姿势控制。
