Venoms are biochemical arsenals that have emerged in numerous animal lineages, where they have co-evolved with morphological and behavioural traits for venom production and delivery. In centipedes, venom evolution is thought to be constrained by the morphological complexity of their venom glands due to physiological limitations on the number of toxins produced by their secretory cells. Here we show that the uneven toxin expression that results from these limitations have enabled Scolopendra morsitans to regulate the composition of their secreted venom despite the lack of gross morphologically complex venom glands. We show that this control is probably achieved by a combination of this heterogenous toxin distribution with a dual mechanism of venom secretion that involves neuromuscular innervation as well as stimulation via neurotransmitters. Our results suggest that behavioural control over venom composition may be an overlooked aspect of venom biology and provide an example of how exaptation can facilitate evolutionary innovation and novelty.

毒液是出现在许多动物谱系中的生化武器库，它们与形态和行为特征共同进化以产生和传递毒液。在蜈蚣中，由于分泌细胞产生的毒素数量的生理限制，毒液进化被认为受到其毒腺形态复杂性的限制。在这里，我们表明，这些限制导致的不均匀毒素表达使 Scolopendra morsitans 能够调节其分泌的毒液的组成，尽管缺乏形态复杂的大体毒腺。我们表明，这种控制可能是通过将这种异质性毒素分布与毒液分泌的双重机制相结合来实现的，该机制涉及神经肌肉神经支配以及通过神经递质的刺激。我们的结果表明，对毒液成分的行为控制可能是毒液生物学中一个被忽视的方面，并提供了一个例子来说明驱逐如何促进进化创新和新颖性。