許多蜘蛛藉由生產絲與建構蜘蛛網來捕食獵物，而蜘蛛的大壺狀腺絲則在圓網中提供了支持及作為骨架之功能。過去研究指出蜘蛛可以因獵物與蜘蛛本身重量之變化而調節其大壺狀腺絲或圓網之物理或化學性質，但對於環境中物理性干擾是否對蜘蛛絲或圓網之特性有所影響仍不清楚。因此，我藉由比較二種生存於不同強風干擾程度環境的塵蛛之絲及網性質，以及在實驗室中操作風速，以研究這些性質是否因環境中干擾而有所不同。結果顯示，棲習在濱海地區的二角塵蛛的大壺狀腺絲之胺基酸組成中具有較高的比例的丙氨酸，而棲習在森林地區的長銀塵蛛則含較多的穀氨醯胺。此外，二角塵蛛大壺狀腺絲的張力與斷裂能比長銀塵蛛高，以致於前者以較少之縱絲便能達到相同程度之網張力。另一方面，施以不同風速操作之蜘蛛雖沒有調節大壺狀腺絲之胺基酸組成及直徑，但是該絲卻具更強之物性以防止圓網破裂；它們並結出更小、更疏之網以減少風阻。這些結果指出棲習於不同強風干擾程度的蜘蛛其絲及圓網具有變異性以及表型可塑性。 Most orb-weaving spiders use silk to construct their web to capture prey. In the orb, the silks produced by major ampullate glands serve as radius and frame to support the structure of whole web. Previous studies show that spiders can adjust the mechanical/chemical properties of spider silk/web in response to prey variation and spider biomass. However, the effects of environmental physical disturbances on these properties are still unclear. By comparing the properties of silk/web of two Cyclosa spiders inhabiting habitats of different level of wind disturbances, I investigated whether spiders would alter silk and web properties in response to such disturbance. I also manipulated wind speed in the laboratory to investigate whether such treatment will affect web/silk properties. The results showed that the major ampullate silk of C. mulmeinensis inhabiting seashores contained higher percentage of glycine and lower glutamine than those of silk from the forest-dwelling C. ginnaga. Moreover, the ultimate tension and breaking energy of major ampullate silk of C. mulmeinensis were higher than those of C. ginnaga. Results of laboratory studies showed that spiders receiving wind disturbance produced stronger major mapullate silk, although silk amino acid composition and diameter did not differ. Spiders subjecting to wind disturbance also built smaller and looser webs to reduce wind drag. These results imply that orb-web spider inhabiting areas of different level of wind disturbances exhibit variation and plasticity in silk and web properties.
