Ganske Anne-Sarah, Uhl Gabriele
Department of General and Systematic Zoology, Zoological Institute and Museum, University of Greifswald, Loitzer Strasse 26, 17489 Greifswald, Germany.
Arthropod Struct Dev. 2018 Mar;47(2):144-161. doi: 10.1016/j.asd.2018.01.001. Epub 2018 Jan 19.
Spiders show a wide range of sensory capabilities as evidenced by behavioural observations. Accordingly, spiders possess diverse sensory structures like mechano-, hygro-, thermo- or chemoreceptive sensilla. As to chemoreceptive structures, only trichoid tip-pore sensilla were found so far that were tested for gustation. That spiders are also able to receive airborne signals is corroborated by numerous behavioural experiments but the responsible structures have not been determined yet. Here, we provide sensilla distribution maps of pedipalps and walking legs of both sexes of the wasp spider Argiope bruennichi whose biology and mating system is well explored. By means of scanning electron microscopy, we scrutinized whether there is in fact only one type of trichoid pore sensillum and if so, if there are deviations in the outer structure of the tip-pore sensilla depending on their position on the body. We also describe the external structure and distribution of slit sense organs, trichobothria and tarsal organs. Our study shows that all four sensillum types occur on pedipalps and walking legs of both sexes. As to chemosensory organs, only tip-pore sensilla were found, suggesting that this sensillum type is used for both gustation and olfaction. The highest numbers of tip-pore sensilla were observed on metatarsi and tarsi of the first two walking legs. Mechanosensitive slit sense organs occur as single slit sensilla in rows along all podomers or as lyriform organs next to the joints. The mechanosensitive trichobothria occur on the basal part of tibiae and metatarsi. Tarsal organs occur on the dorsal side of all tarsi and the male cymbium. The distribution maps of the sensilla are the starting point for further exploration of internal, morphological differences of the sensilla from different regions on the body. Cryptic anatomical differences might be linked to functional differences that can be explored in combination with electrophysiological analyses. Consequently, the maps will help to elucidate the sensory world of spiders.
行为观察表明，蜘蛛具有广泛的感官能力。相应地，蜘蛛拥有多种感官结构，如机械、湿度、温度或化学感受性感器。至于化学感受结构，到目前为止，仅发现了用于味觉测试的毛状尖端孔感器。大量行为实验证实蜘蛛也能够接收空气传播的信号，但尚未确定其负责的结构。在这里，我们提供了横纹金蛛（Argiope bruennichi）雌雄两性的触肢和步足的感器分布图，其生物学和交配系统已得到充分研究。通过扫描电子显微镜，我们仔细研究是否实际上只有一种毛状孔感器，如果是这样，尖端孔感器的外部结构是否因其在身体上的位置而存在差异。我们还描述了 slit 感觉器官、听毛和跗节器官的外部结构和分布。我们的研究表明，所有四种感器类型都出现在雌雄两性的触肢和步足上。至于化学感觉器官，仅发现了尖端孔感器，这表明这种感器类型用于味觉和嗅觉。在前两对步足的跗跖节和跗节上观察到的尖端孔感器数量最多。机械敏感的 slit 感觉器官以单排 slit 感器的形式沿着所有肢节排列，或者在关节旁边以琴形器官的形式出现。机械敏感的听毛出现在胫节和跗跖节的基部。跗节器官出现在所有跗节的背侧和雄性的生殖球上。感器分布图是进一步探索身体不同区域感器内部形态差异的起点。隐秘的解剖学差异可能与功能差异相关，可结合电生理分析进行探索。因此，这些图将有助于阐明蜘蛛的感官世界。
