Oregon Institute of Marine Biology, University of Oregon, Eugene, OR 97405, USA.
Louisiana Universities Marine Consortium, Chauvin, LA 70344, USA.
Sci Adv. 2024 May 17;10(20):eadm9511. doi: 10.1126/sciadv.adm9511. Epub 2024 May 15.
Helical motion is prevalent in nature and has been shown to confer stability and efficiency in microorganisms. However, the mechanics of helical locomotion in larger organisms (>1 centimeter) remain unknown. In the open ocean, we observed the chain forming salp, , swimming in helices. Three-dimensional imaging showed that helicity derives from torque production by zooids oriented at an oblique orientation relative to the chain axis. Colonies can spin both clockwise and counterclockwise and longer chains (>10 zooids) transition from spinning around a linear axis to a helical swimming path. Propulsive jets are non-interacting and directed at a small angle relative to the axis of motion, thus maximizing thrust while minimizing destructive interactions. Our integrated approach reveals the biomechanical advantages of distributed propulsion and macroscale helical movement.
螺旋运动在自然界中很普遍，已被证明在微生物中具有稳定性和效率。然而，较大生物体（>1 厘米）中螺旋运动的力学机制尚不清楚。在开阔的海洋中，我们观察到形成链状的樽海鞘 以螺旋状游动。三维成像表明，螺旋运动源于相对于链轴呈倾斜取向的动物体产生的扭矩。群体可以顺时针和逆时针旋转，较长的链（>10 个动物体）从绕线性轴旋转过渡到螺旋游动路径。推进射流是互不作用的，并且相对于运动轴的角度很小，从而在最小化破坏性相互作用的同时最大限度地提高推力。我们的综合方法揭示了分布式推进和宏观螺旋运动的生物力学优势。
