Right-handed snakes: convergent evolution of asymmetry for functional specialization
Right-handed snakes: convergent evolution of asymmetry for functional specialization
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DOI：
10.1098/rsbl.2006.0600
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发表时间：
2007-04-22
期刊：
影响因子：
3.3
通讯作者：
Hori, Michio
中科院分区：
文献类型：
--
作者：
Hoso, Masaki;Asami, Takahiro;Hori, Michio
在不同动物中发现的外部不对称性具有满足生态要求的关键功能。一些食螺节肢动物表现出方向不对称的觅食效率，因为右旋（顺时针）物种在蜗牛中占压倒性优势。在这里，我们显示收敛的方向不对称性的齿系的蜗牛吃脊椎动物。我们发现，除了不吃蜗牛的蛇外，Pareatinae亚科的蛇在右下颌骨上的牙齿比左下颌骨多。在喂养实验中，一位专门吃蜗牛的专家Pareas iwasakii完成了对右侧柔软身体的提取，比左侧身体更快，下颌骨收缩更少。蛇未能举行和下降左旋蜗牛更经常由于行为不对称时，罢工。我们的结果表明，牙列对称性断裂是一项关键创新，为蛇类掠食者打开了独特的生态位。
External asymmetry found in diverse animals bears critical functions to fulfil ecological requirements. Some snail-eating arthropods exhibit directional asymmetry in their feeding apparatus for foraging efficiency because dextral (clockwise) species are overwhelmingly predominant in snails. Here, we show convergence of directional asymmetry in the dentition of snail-eating vertebrates. We found that snakes in the subfamily Pareatinae, except for non-snail-eating specialists, have more teeth on the right mandible than the left. In feeding experiments, a snail-eating specialist Pareas iwasakii completed extracting a dextral soft body faster with fewer mandible retractions than a sinistral body. The snakes failed in holding and dropped sinistral snails more often owing to behavioural asymmetry when striking. Our results demonstrate that symmetry break in dentition is a key innovation that has opened a unique ecological niche for snake predators.