THE KINEMATICS OF SWIMMING IN ANURAN LARVAE
THE KINEMATICS OF SWIMMING IN ANURAN LARVAE
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发表时间：
1985-11
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通讯作者：
R. Wassersug;K. Hoff
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作者：
R. Wassersug;K. Hoff
利用计算机辅助分析高速（≥200帧s-1）电影记录，研究了四种无尾类（牛蛙、北蛙、蛤蛙和美洲蟾蜍）蝌蚪的游泳运动学。1.蝌蚪表现出同样的积极，线性关系之间的尾巴拍频率和特定的游泳速度通常报告的subcarangiform鱼类。2.蝌蚪的尾拍的最大振幅随着游泳速度的增加而增加，直到大约4个长度s-1。超过4个长度s-1，振幅在大约25%的长度处接近渐近线。3.尾巴相对较长的蝌蚪具有较低的比振幅。4.蝌蚪的弗劳德效率与大多数亚carangiform鱼类的弗劳德效率相似。5.蟾蜍幼虫往往有更高的特定最大振幅，更高的尾拍频率，较低的螺旋桨效率（至少在中等速度）和轴向肌肉组织比相当大小的蛙幼虫。这些差异可能与蟾蜍幼虫对许多潜在的捕食者是有害的这一事实有关，因此不需要仅仅依靠运动进行防御。6.蝌蚪在吻部表现出比大多数成鱼更大的横向运动。7.蝌蚪在游泳过程中最少横向运动的点是在半圆形管道的水平上，正如脊椎动物内耳进化模型中所假设的那样。8.被动振荡麻醉和curized蝌蚪在其尾巴的基础上产生正常的运动学在其余的尾巴。这支持了这样的观点：在正常、直接的恒速游泳过程中，蝌蚪尾巴后部锥形部分的肌肉活动在推力产生中并不起主要作用。9.当尾尖穿过运动路径时，它的迎角和横向速度与如何产生推力的理论预测不一致。在尾鳍高点（大约中尾）评估的相同参数表明，尾鳍的这一部分产生的推力最有效。10.消融的尾巴在被动振荡的蝌蚪的末端证实，蝌蚪尾巴的终端部分用于减少过度的振幅在更前部的尾巴，其中最推力产生。11.尾巴的后部在减少蝌蚪周围的湍流方面很重要。它还可以在不规则的复杂运动中产生推力，例如向后游泳。12.蝌蚪在最大游泳速度和机械效率方面与相似大小的亚carangiform鱼类相当，尽管它们的轴向肌肉组织少得多，并且缺乏鱼类中覆盖鳍的复杂骨骼元件。蝌蚪尾巴的简单形状似乎允许这些动物在短距离内有效运动和高机动性，同时保持在变态时快速形态变化的潜力。
The kinematics of swimming in tadpoles from four species of anurans ( Rana catesbeiana Shaw, Rana septentrionalis Baird, Rana clamitans Latreille and Bufo americanus Holbrook) was studied using computer-assisted analysis of high speed (≥200 frames s −1 ) cine records. 1. Tadpoles exhibit the same positive, linear relationship between tail beat frequency and specific swimming speed commonly reported for subcarangiform fishes. 2. Tadpoles show an increase in the maximum amplitude of the tail beat with increasing swimming speed up to approximately 4 lengths s −1 . Above 4 lengths s −1 , amplitude approaches an asymptote at approximately 25 % of length. 3. Tadpoles with relatively longer tails have lower specific amplitudes. 4. Froude efficiencies for tadpoles are similar to those reported for most subcarangiform fishes. 5. Bufo larvae tend to have higher specific maximum amplitude, higher tail beat frequencies, lower propeller efficiencies (at least at intermediate speeds) and substantially less axial musculature than do comparable-sized Rana larvae. These differences may relate to the fact that Bufo larvae are noxious to many potential predators and consequently need not rely solely on locomotion for defence. 6. Tadpoles exhibit larger amounts of lateral movement at the snout than do most adult fishes. 7. The point of least lateral movement during swimming in tadpoles is at the level of the semi-circular canals, as assumed in models on the evolution of the vertebrate inner ear. 8. Passive oscillation of anaesthetized and curarized tadpoles at the base of their tail produces normal kinematics in the rest of the tail. This supports the idea that muscular activity in the posterior, tapered portion of the tadpole tail does not serve a major role in thrust production during normal, straightforward swimming at constant velocity. 9. The angle of incidence and lateral velocity of the tail tip as it crosses the path of motion are not consistent with theoretical predictions of how thrust should be generated. The same parameters evaluated at the high point of the tail fin (approximately midtail) suggest that that portion of the tail generates thrust most effectively. 10. Ablation of the end of the tail in passively oscillated tadpoles confirms that the terminal portion of the tadpole tail serves to reduce excessive amplitude in the more anterior portion of the tail, where most thrust is generated. 11. The posterior portion of the tail is important in reducing turbulence around a tadpole. It may also function to produce thrust during irregular, intricate movements, such as swimming backwards. 12. Tadpoles are comparable to subcarangiform fishes of similar size in their maximum swimming speed and mechanical efficiency, despite the fact that they have much less axial musculature and lack the elaborate skeletal elements that stiffen the fins in fishes. The simple shape of the tadpole tail appears to allow these animals efficient locomotion over short distances and high manoeuvrability, while maintaining the potential for rapid morphological change at metamorphosis.