Luo Xiao-Zhu, Wipfler Benjamin, Ribera Ignacio, Liang Hong-Bin, Tian Ming-Yi, Ge Si-Qin, Beutel Rolf G
Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, 100101 Beijing, PR China; Department of Entomology, College of Agriculture, South China Agricultural University, 510642 Guangzhou, PR China; Institut für Zoologie und Evolutionsforschung, Friedrich-Schiller-University Jena, Erbertstr. 1, 07743 Jena, Germany.
Zoologisches Forschungsmuseum Alexander Koenig (ZFMK), Adenauerallee 160, 53113 Bonn, Germany.
Arthropod Struct Dev. 2018 Nov;47(6):662-674. doi: 10.1016/j.asd.2018.09.001. Epub 2018 Oct 6.
External and internal thoracic structures of two carabid species (Trechini) were examined and documented with different techniques. The study has a main focus on the eyeless cave-dwelling specialist Sinaphaenops wangorum, but detailed information is also provided for a species occurring in cave entrances. The phylogenetic background of the structural features of the thoracic skeletomuscular system was addressed. The thoracic morphology of the examined species was compared to conditions observed in previously studied carabids and non-related subterranean leiodids (Staphylinoidea) in order to identify cave adaptations. Main thoracic character complexes linked with cavernicolous habits in Trechini are elongation of the pro- and mesothorax and the legs, and a complete and irreversible reduction of the flight apparatus. The lost flight capacity is linked with a far reaching modification of skeletal elements of the metathorax including a strongly shortened and simplified metanotum, a shortened metaventrite, and completely reduced wings and sclerites of the wing base. The elongate prothorax together with the long and slender head and elongated legs distinctly increases the activity range in the subterranean lightless environment, which likely facilitates foraging of the carnivorous beetles. Some of the observed features like wing loss and elongation of the anterior thorax and legs are also found in some cave-dwelling Leiodidae (Leptodirini), whereas some other subterranean members of the staphylinoid family have a compact body and legs of normal length. In contrast to the predaceous Trechini, Leptodirini are scavengers.
运用不同技术对两种步甲科（Trechini）昆虫的胸部外部和内部结构进行了检查和记录。该研究主要聚焦于无眼的洞穴栖息专家王氏华隐翅虫（Sinaphaenops wangorum），但也提供了一种出现在洞穴入口处的物种的详细信息。探讨了胸部骨骼肌肉系统结构特征的系统发育背景。将所研究物种的胸部形态与先前研究的步甲科昆虫以及非相关地下隐翅虫科（Staphylinoidea）昆虫所观察到的情况进行比较，以确定洞穴适应性。Trechini中与洞穴生活习性相关的主要胸部特征复合体包括前胸和中胸以及腿部的伸长，以及飞行器官的完全且不可逆的退化。飞行能力的丧失与后胸骨骼元素的广泛改变有关，包括强烈缩短和简化的后胸背板、缩短的后胸腹板，以及翅膀和翅基部骨片的完全退化。伸长的前胸与细长的头部和伸长的腿部一起，明显增加了在地下无光环境中的活动范围，这可能有利于肉食性甲虫觅食。一些观察到的特征，如翅膀退化以及前胸和腿部伸长，在一些洞穴栖息的隐翅虫科（Leptodirini）中也有发现，而隐翅虫科的其他一些地下成员身体紧凑，腿部长度正常。与肉食性的Trechini不同，Leptodirini是食腐动物。
