Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten 9, 24118, Kiel, Germany.
Commun Biol. 2023 Dec 6;6(1):1232. doi: 10.1038/s42003-023-05575-7.
To adhere their silk threads for the construction of webs and to fix the dragline, spiders produce attachment discs of piriform silk. Uniquely, the aquatic spider Argyroneta aquatica spends its entire life cycle underwater. Therefore, it has to glue its attachment discs to substrates underwater. Here we show that Argyroneta aquatica applies its thread anchors within an air layer around the spinnerets maintained by superhydrophobic setae. During spinning, symmetric movements of the spinnerets ensure retaining air in the contact area. The flat structure of the attachment discs is thought to facilitate fast curing of the piriform adhesive cement and improves the resistance against drag forces. Pull-off tests on draglines connected with attachment discs on different hydrophilic substrates point to dragline rupture as the failure mode. The Young´s modulus of the dragline (8.3 GPa) is within the range as in terrestrial spiders. The shown structural and behavioral adaptations can be the model for new artificial underwater gluing devices.
为了将丝线固定在网上并固定拖丝，蜘蛛会产生梨形丝的附着盘。独特的是，水生蜘蛛 Argyroneta aquatica 在其整个生命周期都在水下度过。因此，它必须将其附着盘粘在水下的基质上。在这里，我们展示了 Argyroneta aquatica 将其线锚定在由超疏水刚毛维持的喷丝头周围的气层内。在纺丝过程中，喷丝头的对称运动确保了接触区域内的空气保留。附着盘的扁平结构被认为有助于快速固化梨形粘性水泥，并提高对拖曳力的抵抗力。在不同亲水基质上连接附着盘的拖丝上进行的拉拔测试表明，拖丝断裂是失效模式。拖丝的杨氏模量（8.3GPa）在与陆地蜘蛛相同的范围内。所示的结构和行为适应性可以作为新型水下粘胶装置的模型。
