Puri Sahil, Aegerter-Wilmsen Tinri, Jaźwińska Anna, Aegerter Christof M
Physik-Institut, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
J Exp Biol. 2018 Feb 20;221(Pt 4):jeb171777. doi: 10.1242/jeb.171777.
The caudal fins of adult zebrafish are supported by multiple bony rays that are laterally interconnected by soft interray tissue. Little is known about the fin's mechanical properties that influence bending in response to hydrodynamic forces during swimming. Here, we developed an experimental setup to measure the elastic properties of caudal fins by applying micro-Newton forces to obtain bending stiffness and a tensional modulus. We detected overall bending moments of 1.5×10-4×10 N m along the proximal-distal axis of the appendage showing a non-monotonous pattern that was not due to the geometry of the fin itself. Surgical disruption of the interray tissues along the proximal-distal axis revealed no significant changes to the overall bending stiffness, which we confirmed by determining a tensional modulus of the interray tissue. Thus, the biophysical values suggest that the flexibility of the fin during its hydrodynamic performance predominantly relies on the mechanical properties of the rays.
成年斑马鱼的尾鳍由多条骨质鳍条支撑，这些鳍条通过柔软的鳍条间组织横向互连。对于鳍在游泳过程中响应水动力而弯曲的力学特性，我们知之甚少。在此，我们开发了一种实验装置，通过施加微牛顿力来测量尾鳍的弹性特性，以获得弯曲刚度和拉伸模量。我们在附属肢体的近端 - 远端轴上检测到1.5×10⁻⁴×10 N·m的整体弯矩，呈现出非单调模式，这并非由鳍本身的几何形状所致。沿近端 - 远端轴对鳍条间组织进行手术破坏后，整体弯曲刚度没有显著变化，我们通过测定鳍条间组织的拉伸模量证实了这一点。因此，生物物理值表明，鳍在其水动力性能期间的柔韧性主要依赖于鳍条的力学特性。
