Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut, USA.
Department of Biology, University of Washington, Seattle, Washington, USA.
J Morphol. 2021 Jan;282(1):127-145. doi: 10.1002/jmor.21287. Epub 2020 Oct 22.
We investigated the functional morphology of lingual prey capture in the blue-tongued skink, Tiliqua scincoides, a lingual-feeding lizard nested deep within the family Scincidae, which is presumed to be dominated by jaw-feeding. We used kinematic analysis of high-speed video to characterize jaw and tongue movements during prey capture. Phylogenetically informed principal components analysis of tongue morphology showed that, compared to jaw-feeding scincids and lacertids, T. scincoides and another tongue-feeding scincid, Corucia zebrata, are distinct in ways suggesting an enhanced ability for hydrostatic shape change. Lingual feeding kinematics show substantial quantitative and qualitative variation among T. scincoides individuals. High-speed video analysis showed that T. scincoides uses significant hydrostatic elongation and deformation during protrusion, tongue-prey contact, and retraction. A key feature of lingual prey capture in T. scincoides is extensive hydrostatic deformation to increase the area of tongue-prey contact, presumably to maximize wet adhesion of the prey item. Adhesion is mechanically reinforced during tongue retraction through formation of a distinctive "saddle" in the foretongue that supports the prey item, reducing the risk of prey loss during retraction.
我们研究了蓝舌石龙子（Tiliqua scincoides）在捕食猎物时的舌部功能形态，这种蜥蜴是舌咽式进食的蜥蜴，隶属于石龙子科（Scincidae），其被认为主要以颌部进食为主。我们使用高速录像的运动学分析来描述捕食猎物过程中颌部和舌部的运动。基于系统发育的舌部形态主成分分析表明，与以颌部进食为主的石龙子科和蜥蜴科相比，蓝舌石龙子和另一种舌咽式进食的石龙子科动物 Corucia zebrata 在某些方面存在明显的差异，这表明它们具有更强的流体静力形状变化能力。蓝舌石龙子的舌部进食运动学在个体之间存在显著的定量和定性差异。高速录像分析表明，蓝舌石龙子在伸出、舌部接触猎物和缩回过程中，会显著地进行流体静力伸长和变形。蓝舌石龙子舌部捕食猎物的一个关键特征是广泛的流体静力变形，以增加舌部与猎物的接触面积，从而最大限度地提高猎物的湿粘附力。在舌部缩回过程中，前舌部形成独特的“鞍部”来支撑猎物，从而通过形成这种结构来增强粘附力，降低猎物在缩回过程中丢失的风险。
