Ultrastructure of Solifugae (Arachnida) - comparative studies of organ systems with special focus on functional analyses and phylogenetic interpretations

避日类是蛛形纲的一个中等多样性目，除澳大利亚外，在世界各地的温暖/炎热地区都有分布。它们通常被描述为一组代表一个特殊的混合物的plesiomorphic和apporphic字符。描述蛛形纲内部关系的枝藻通常显示假蝎目是避日纲的姐妹类群。然而，这种关系是基于非常少，穷人或可疑的字符（主要是形状和插入的螯，rostrosoma）。关于其他特征，两个分类群是惊人的不同。我们的比较研究的男性生殖系统的避日螨，拟蝎和阿卡里揭示了显着的apomorphic相似性避日螨和放线螨。最近的分子数据是模糊的。因此，所提出的避日植物的系统位置仍然是相当推测性的。造成这种不确定性，模糊或矛盾的解释的主要原因当然是对这些蜘蛛的知识贫乏。因此，本研究旨在研究来自不同家庭的避日植物的超微结构，主要包括生殖系统，消化器官，包括口器，呼吸系统，心脏，排泄系统和感觉结构，同时考虑到少年阶段。

Solifugae represent a meso-diverse order of Arachnida which occurs world wide in warm/hot regions except for Australia. They are usually described as a group representing a peculiar mixture of plesiomorphic and apomorphic characters. Cladograrns depicting relationships within Arachnida most often show Pseudoscorpiones as the sister group of Solifugae. However, this relationship is based on very few, poor or doubtful characters (mainly shape and insertion of chelicerae, rostrosoma). Regarding other characteristics both taxa are strikingly different. Our comparative studies of male genital systems of Solifugae, Pseudoscorpiones and Acari have revealed striking apomorphic similarities between Solifugae and actinotrichid mites. Recent molecular data are ambiguous. Thus, the suggested systematic position of Solifugae remains rather speculative. The main reason causing such uncertainty, vague or contradictory interpretations is certainly the poor knowledge on these arachnids. Hence, the present study intends to study Solifugae from different families with regard to ultrastructure including predominantly genital systems, alimentary organs including the mouthparts, respiratory systems, heart, excretory systems, and sensory structures taking also juvenile stages into account.