Pekár Stano, Šedo Onřej, Líznarová Eva, Korenko Stanislav, Zdráhal Zdeněk
Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic,
Naturwissenschaften. 2014 Jul;101(7):533-40. doi: 10.1007/s00114-014-1189-8. Epub 2014 May 31.
It is rare to find a true predator that repeatedly and routinely kills prey larger than itself. A solitary specialised ant-eating spider of the genus Zodarion can capture a relatively giant prey. We studied the trophic niche of this spider species and investigated its adaptations (behavioural and venomic) that are used to capture ants. We found that the spider captures mainly polymorphic Messor arenarius ants. Adult female spiders captured large morphs while tiny juveniles captured smaller morphs, yet in both cases ants were giant in comparison with spider size. All specimens used an effective prey capture strategy that protected them from ant retaliation. Juvenile and adult spiders were able to paralyse their prey using a single bite. The venom glands of adults were more than 50 times larger than those of juvenile spiders, but the paralysis latency of juveniles was 1.5 times longer. This suggests that this spider species possesses very potent venom already at the juvenile stage. Comparison of the venom composition between juvenile and adult spiders did not reveal significant differences. We discovered here that specialised capture combined with very effective venom enables the capture of giant prey.
很少能找到一种真正的捕食者会反复且常规地捕杀比自身更大的猎物。一种独居的、专门捕食蚂蚁的佐达蛛属蜘蛛能够捕获相对巨大的猎物。我们研究了这种蜘蛛的营养生态位，并调查了其用于捕获蚂蚁的适应性（行为和毒液方面）。我们发现这种蜘蛛主要捕食多态的沙蚁。成年雌性蜘蛛捕获大型形态的沙蚁，而微小的幼蛛捕获较小形态的沙蚁，但在这两种情况下，与蜘蛛大小相比，蚂蚁都算是巨大的。所有标本都采用了一种有效的猎物捕获策略，使它们免受蚂蚁的反击。幼蛛和成年蜘蛛都能一口咬下去使猎物麻痹。成年蜘蛛的毒腺比幼蛛的毒腺大50多倍，但幼蛛的麻痹潜伏期却是成年蜘蛛的1.5倍。这表明这种蜘蛛在幼蛛阶段就已经拥有非常强效的毒液。对幼蛛和成年蜘蛛毒液成分的比较并未发现显著差异。我们在此发现，专门的捕获方式与非常有效的毒液相结合，使得捕获巨大猎物成为可能。
