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The Surprising Secret of Snakes’ Venomous Bites
自然界的“绝命毒师”：毒蛇咬人的惊人秘密
The world hosts hundreds of wildly different venomous snake species, from brightly banded coral snakes to camouflaged cottonmouths. But somehow even distantly related species independently evolved specialized fangs with venom-carrying grooves—a longtime puzzle spurring new research into how this could have happened. The answer, says Flinders University herpetologist Alessandro Palci, has been hiding inside the serpents' mouths all along.
世界上有数百种截然不同的毒蛇，从条纹鲜艳的珊瑚蛇到伪装的水腹蛇。但不知何故，即使是远亲物种也独立进化出了带有毒液凹槽的特殊毒牙——这是长期的未解之谜，促使人们对此进行新的研究。弗林德斯大学爬行动物学家亚历山德罗·帕尔奇表示，答案一直藏在蛇的嘴里。
It turns out that the teeth of most snake species, Palci and his co-authors report in the Proceedings of the Royal Society B, have a ring of tiny indentations around their bases. This pitted tooth tissue, called plicidentine, helps to anchor the teeth to the jaws. “Before our study, plicidentine was thought to be limited to only three types of lizards among living reptiles,” Palci says. In fact, the study finds, it seems to be ubiquitous in snakes.
帕尔奇和他的共同作者在《英国皇家学会学报B》上报道，事实表明，大多数蛇类的牙齿在它们的根部周围都有一圈微小的凹痕。这种凹凸不平的牙齿组织叫做折状牙齿，有助于将牙齿固定在颌骨上。帕尔奇说：“在我们的研究之前，在现存的爬行动物中，折状牙齿被认为只存在于三种蜥蜴中。”事实上，研究发现，它似乎在蛇类中无处不在。
And these dental anchors have taken on another function in venomous species, the researchers say. They used microscopic tissue sampling and micro CT scans of snake teeth to determine that in the teeth nearest a snake's venom glands, the plicidentine's folds have evolved into longer grooves that help snake venom flow from gland to tooth—and then into prey. This result suggests that modern venomous snake species did not have to start from evolutionary scratch every time they developed a deadly bite.
研究人员说，这些“牙齿锚”对有毒物种有另一种作用。他们对蛇的牙齿进行了显微组织取样和显微CT扫描，以确定在最靠近蛇毒腺的牙齿中，折状牙齿的褶皱已经进化成更长的凹槽，帮助蛇毒从腺流向牙齿，然后进入猎物。这一结果表明，现代毒蛇物种不必每次进化出致命的咬伤都从头开始。
