Stinson Charlotte M, Deban Stephen M
Department of Integrative Biology, University of South Florida, 4202 East Fowler Avenue, Tampa, FL 33620, USA; Department of Biology, California State University, Bakersfield, 9001 Stockdale Highway, Bakersfield, CA 93311, USA.
Department of Integrative Biology, University of South Florida, 4202 East Fowler Avenue, Tampa, FL 33620, USA.
Zoology (Jena). 2017 Dec;125:69-78. doi: 10.1016/j.zool.2017.08.004. Epub 2017 Aug 19.
During aquatic feeding salamanders use the hyobranchial apparatus to capture prey. The hyobranchial apparatus depresses the floor of the mouth, effectively expanding the oropharyngeal cavity and generating suction. Within the family Salamandridae, there is a wide range of ecological diversity, with salamanders being terrestrial, semi-aquatic, or aquatic as adults. The purpose of this research was to quantify the diverse morphology and suction feeding performance of aquatically feeding salamandrids. We hypothesized that a more robust hyobranchial apparatus morphology would yield increased aquatic feeding performance. When compared to semi-aquatic newts, the fully aquatic species Paramesotriton labiatus had greater mineralization of the hyobranchial apparatus, as well as relatively more narrow basibranchial and wider ceratobranchial I+II complexes. These morphological differences coincide with greater aquatic feeding performance. Kinematics from high-speed videography revealed that maximum mouth opening velocity and acceleration were approximately two and five times greater, respectively, in Paramesotriton, and hyobranchial depression acceleration was found to be approximately three times greater than in the semi-aquatic species Pleurodeles waltl, Notophthalmus viridescens, Triturus dobrogicus, and Cynops cyanurus. Using digital particle image velocimetry, peak and average fluid velocity generated in Paramesotriton during suction feeding events were found to be 0.5ms and 0.2ms, respectively, doubling that of all semi-aquatic species. These findings reveal that specialized morphology increases aquatic feeding performance in a fully aquatic newt.
在水生摄食过程中，蝾螈利用鳃器捕捉猎物。鳃器压低口腔底部，有效地扩大口咽腔并产生吸力。在蝾螈科中，生态多样性范围广泛，成年蝾螈有陆生、半水生或水生的。本研究的目的是量化水生摄食蝾螈科动物的多样形态和吸力摄食性能。我们假设更健壮的鳃器形态会带来更高的水生摄食性能。与半水生蝾螈相比，完全水生的种——唇褶瘰螈（Paramesotriton labiatus）的鳃器矿化程度更高，且基鳃骨相对更窄，角鳃骨I+II复合体更宽。这些形态差异与更高的水生摄食性能相一致。高速摄像的运动学研究表明，唇褶瘰螈的最大张口速度和加速度分别约为半水生物种疣螈（Pleurodeles waltl）、绿红东美螈（Notophthalmus viridescens）、杜氏欧螈（Triturus dobrogicus）和蓝尾火腹蝾螈（Cynops cyanurus）的两倍和五倍，且鳃器下压加速度约为它们的三倍。使用数字粒子图像测速技术发现，唇褶瘰螈在吸力摄食事件中产生的峰值和平均流体速度分别为0.5米/秒和0.2米/秒，是所有半水生物种的两倍。这些发现表明，特殊的形态提高了完全水生蝾螈的水生摄食性能。
