Animals that live by rivers may benefit from being able to cross them, but behavioral adaptations are needed. Additionally, being able to remain submerged is also important if the animal moves under water. Here we asked whether the harvestman Heteromitobates discolor (Opiliones), that lives by rivers, (a) can propel itself across the water surface, (b) moves into the water if disturbed and (c) can survive for long periods when submerged. Heteromitobates discolor exhibited two gaits on water, whereas a strictly terrestrial species was not able to propel itself. When experimentally submitted to simulated predator attack on a rock on the river, H. discolor walked onto the water, while a strictly terrestrial species did not. Finally, it was able to survive for 6 h under water, presumably due to the conspicuous air film that formed around its body, which was also observed in a strictly terrestrial species. Altogether, these observations suggest that the aquatic environment is not a barrier for regular activity and can be used as an extension of the terrestrial environment for H. discolor.

中文翻译：

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河岸收割机的水下运动和生存（Opiliones，Arachnida）

生活在河流边的动物可能会从能够穿越河流中受益，但需要进行行为适应。此外，如果动物在水下移动，能够保持水下也很重要。在这里，我们询问了生活在河流中的收割者 Heteromitobates 变色（Opiliones）是否（a）可以推动自己穿过水面，（b）如果受到干扰就会进入水中，以及（c）在淹没时可以存活很长时间。Heteromitobates discolor 在水上表现出两种步态，而严格的陆生物种则无法推进自己。当实验性地接受模拟捕食者对河上岩石的攻击时，变色龙走到水面上，而严格的陆生物种则没有。最后，它能够在水下存活 6 小时，大概是因为它的身体周围形成了明显的空气膜，这也在严格的陆生物种中观察到。总而言之，这些观察结果表明，水生环境不是常规活动的障碍，可以用作变色嗜血菌的陆地环境的延伸。