Lemell Patrick, Lemell Christoph, Snelderwaard Peter, Gumpenberger Michaela, Wochesländer Robert, Weisgram Josef
Department of Comparative Anatomy and Morphology, Institute of Zoology, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria.
J Exp Biol. 2002 May;205(Pt 10):1495-506. doi: 10.1242/jeb.205.10.1495.
The kinematics of feeding on fish have been studied in the aquatic feeding specialist Chelus fimbriatus, the fringed turtle, to provide a basic description of complete feeding cycles. Anatomical findings supplement the kinematic results. High-speed video (500 frames x s(-1)) recordings and X-ray film (150 frames x s(-1)) are used to analyse the kinematic variables characterizing head, hyoid, oesophageal and prey movements. The high velocities, especially of mouth opening, the forward thrust of the head and suction of the prey, are unique among turtles and comparable with those of aquatic salamanders and certain fishes (unidirectional feeders, in contrast to Chelus fimbriatus). The expandability of the pharynx and the anterior half of the oesophagus enables a specific type of unidirectional flow, at least during the early stages of the feeding cycle. This considerably improves the feeding performance compared with that of other aquatic turtles. The streamlined shape of the skull, the large hyoid apparatus, the highly reduced tongue and the extremely distensible oesophagus support the kinematics to a great extent, making C. fimbriatus a specialized suction feeder that can be regarded as one endpoint in the feeding evolution of aquatic reptiles.
为了对完整的摄食周期进行基本描述，人们对食鱼的水生摄食专家——玛塔龟（Chelus fimbriatus）的摄食运动学进行了研究。解剖学研究结果对运动学研究结果起到了补充作用。利用高速视频（500帧·秒⁻¹）记录和X光胶片（150帧·秒⁻¹）来分析表征头部、舌骨、食管和猎物运动的运动学变量。玛塔龟的高速度，尤其是张口速度、头部向前推力和猎物吸力，在龟类中是独一无二的，可与水生蝾螈和某些鱼类（与玛塔龟不同，它们是单向摄食者）相媲美。咽和食管前半部分的可扩展性使得至少在摄食周期的早期阶段能够形成一种特定类型的单向流动。与其他水龟相比，这大大提高了摄食性能。头骨的流线型形状、大型舌骨器、高度退化的舌头以及极具扩张性的食管在很大程度上支持了其运动学，使玛塔龟成为一种特殊的吸食性摄食者，可被视为水生爬行动物摄食进化的一个端点。
