机敏异漏斗蛛不同感觉对捕食和趋向行为的影响

Effect of different sensory stimuli on the predatory and approach behavior of the funnel-web spider Allagelena difficilis(Fox)(Araneae: Agelenidae)

【目的】蜘蛛的感觉在发现猎物和捕食过程中起重要作用,研究机敏异漏斗蛛Allagelena difficilis(Fox)的不同感觉对其捕食和趋向行为的影响,有助于揭示影响漏斗蛛捕猎的主要感觉因素及其机制。【方法】视觉屏蔽法、"Y"型嗅觉仪法、去除蛛网法等方法。【结果】视觉和嗅觉对机敏异漏斗蛛的捕食量和趋向行为无显著影响,但蛛网的存在对其捕食量影响明显:视觉屏蔽与未屏蔽的机敏异漏斗蛛24 h捕食黑腹果蝇Drosophila melanogaster Meigen量分别为25.20头/管和26.00头/管,两者之间差异不显著;嗅觉测试发现,在不同的气流条件下,机敏异漏斗蛛停留、选择有猎物管臂和对照管臂的数量之间差异均不显著;另外,该蛛在无蛛网情况下也可捕食,但捕食量极低,与已结网蛛之间的捕食量差异极显著(P<0.01),随着蛛网的修复,两者之间捕食量差距逐渐减小,至24 h时,两者捕食量相近。【结论】机敏异漏斗蛛主要通过机械感觉线索感受蛛网振动、听觉以及猎物的直接碰触发现和捕获猎物,视觉和嗅觉对其捕食行为影响不明显。

Spiders senses play an important role in the process of prey detection and capture. By studying the effects of Allagelena difficilis （Fox） senses on their prey-capture and approach behavior,, we can gain a better understanding the primary factors underlying fiinnel-web spider predation. [Methods] Y-tube olfactometer test, visual shielding test and web-removal test were conducted under laboratory conditions. [Results] The visual and olfactory senses of A. difficilis had little influence on its approach to prey and predation behavior, but the spider’s web had a significant effect on these behaviors： there was no significant difference in the number of A.difficilis that chose the fork containing preys in the Y-tube olfactometer and those that did not （P〉0.05）, and prey consumption of A.difficilis whose eyes were shielded with black ink was also not significantly different to those whose eyes were not shielded （P〉0.05）. However, the prey consumption of spiders whose webs had been removed was significantly lower （P〈0.01） than those which had not had their webs removed. After the removed webs had been repaired, the prey consumption of the both spider groups was similar. [Conclusion] A. difficilis depends primarily on mechanical senses transmitted via its web to detect and capture prey rather than on visual and olfactory senses. Vibratory / acoustic and tactile cues may be important factors affecting the prey-capture behavior of A. difficilis.