In the context of evolutionary arthopodial transformations, centipede ultimate legs exhibit a plethora of morphological modifications and behavioral adaptations. Many species possess significantly elongated, thickened, or pincer-like ultimate legs. They are frequently sexually dimorphic, indicating a role in courtship and mating. In addition, glandular pores occur more commonly on ultimate legs than on walking legs, indicating a role in secretion, chemical communication, or predator avoidance. In this framework, this study characterizes the evolutionarily transformed ultimate legs in Lithobius forficatus in comparison with regular walking legs. A comparative analysis using macro-photography, SEM, μCT, autofluorescence, backfilling, and 3D-reconstruction illustrates that ultimate legs largely resemble walking legs, but also feature a series of distinctions. Substantial differences are found with regard to aspects of the configuration of specific podomeres, musculature, abundance of epidermal glands, typology and distribution of epidermal sensilla, and architecture of associated nervous system structures. In consideration of morphological and behavioral characteristics, ultimate legs in L. forficatus primarily serve a defensive, but also a sensory function. Moreover, morphologically coherent characteristics in the organization of the ultimate leg versus the antenna-associated neuromere point to constructional constraints in the evolution of primary processing neuropils.

中文翻译：

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具有功能意义的蜈蚣 Lithobius forficatus (Myriapoda) 最终腿和行走腿的比较形态

在进化节肢动物转变的背景下，蜈蚣的终极腿表现出过多的形态改变和行为适应。许多物种拥有明显拉长、加厚或钳状的终极腿。它们经常是两性异形的，表明在求爱和交配中的作用。此外，最终腿上的腺孔比行走腿上更常见，这表明在分泌、化学交流或避免捕食者方面发挥作用。在这个框架中，本研究描述了与普通步行腿相比，Lithobius forficatus 进化转变的终极腿。使用宏观摄影、SEM、μCT、自发荧光、回填和 3D 重建的比较分析表明，最终腿在很大程度上类似于步行腿，而且还具有一系列的区别。在特定足节的配置、肌肉组织、表皮腺体的丰度、表皮感受器的类型和分布以及相关神经系统结构的结构方面发现了实质性差异。考虑到形态和行为特征，L. forficatus 的最终腿主要用于防御，但也具有感觉功能。此外，最终腿组织与天线相关神经元的形态学特征表明初级处理神经细胞的进化存在结构限制。表皮感受器的类型和分布，以及相关神经系统结构的结构。考虑到形态和行为特征，L. forficatus 的最终腿主要用于防御，但也具有感觉功能。此外，最终腿组织与天线相关神经元的形态学特征表明初级处理神经细胞的进化存在结构限制。表皮感受器的类型和分布，以及相关神经系统结构的结构。考虑到形态和行为特征，L. forficatus 的最终腿主要用于防御，但也具有感觉功能。此外，最终腿组织与天线相关神经元的形态学特征表明初级处理神经细胞的进化存在结构限制。