Is the Evolution of Viviparity Accompanied by a Relative Increase in Maternal Abdomen Size in Lizards?
Is the Evolution of Viviparity Accompanied by a Relative Increase in Maternal Abdomen Size in Lizards?
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DOI：
10.1007/s11692-012-9166-7
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发表时间：
2012-02
影响因子：
2.5
通讯作者：
Yan-Yan Sun-Yan;Yu Du;Jing Yang;Tianfei Fu;Chixian Lin;X. Ji
中科院分区：
文献类型：
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作者：
Yan-Yan Sun-Yan;Yu Du;Jing Yang;Tianfei Fu;Chixian Lin;X. Ji
胎生生殖的雌性爬行动物应该为它们的卵留出空间，以便在输卵管中达到最大的质量和体积。胎生的进化是否伴随着母体腹部尺寸的相对增大，从而使胎生的雌性增加了产卵的空间？为了回答这个问题，我们以三对不同生殖方式的蜥蜴为研究对象，比较了两种eremias、两种eutropisas和两种ophrynocephalusia的卵生和胎生物种的形态和生殖产量。每对蜥蜴的形态不同，但在腹部和头部大小的两性二态性模式以及生殖产量随母体身体和腹部大小的增加而增加的速度方面是相似的。产后雌性在胎生物种中体重更重，这表明雌性在为竞争需求分配能量时所采取的策略在卵生和胎生物种之间是不同的。与同类的卵生种属相比，一个胎生种属的生殖产量增加，而另外两个胎生种属的生殖产量下降。卵的空间需要量在一种雌对的胎生雌对和胎生雌对之间没有差异，但在其他两种雌对的胎生雌对卵的空间需要量更大。在这两种鱼中，胎生的雌鱼比胎生的雌鱼产的蛋更多，不是因为腹部的相对大小增加，而是因为卵更多。在三个物种对中，考虑到身体大小后，母体腹部大小都没有胎生物种大。我们的数据表明，在蜥蜴中，胎生的进化并不伴随着母体腹部大小的相对增加。未来的工作可以有效地研究其他蜥蜴谱系，以确定我们的结果是否适用于所有蜥蜴。
Female reptiles with viviparous reproduction should leave space for their eggs that reach the maximum mass and volume in the oviducts. Is the evolution of viviparity accompanied by a relative increase in maternal abdomen size, thus allowing viviparous females to increase the amount of space for eggs? To answer this question, we compared morphology and reproductive output between oviparous and viviparous species using three pairs of lizards, which included twoEremias, twoEutropisand twoPhrynocephalusspecies with different reproductive modes. The two lizards in each pair differed morphologically, but were similar in the patterns of sexual dimorphism in abdomen and head sizes and the rates at which reproductive output increased with maternal body and abdomen sizes. Postpartum females were heavier in viviparous species, suggesting that the strategy adopted by females to allocate energy towards competing demands differs between oviparous and viviparous species. Reproductive output was increased in one viviparous species, but decreased in the other two, as compared with congeneric oviparous species. The space requirement for eggs did not differ between oviparous and viviparous females in one species pair, but was greater in viviparous females in the other two pairs greater in relative clutch mass and relative litter mass. In the twoPhrynocephalusspecies, viviparous females produced heavier clutches than did oviparous females not by increasing the relative size of the abdomen, but by being more full of eggs. In none of the three species pairs was the maternal abdomen size greater in the viviparous species after accounting for body size. Our data show that the evolution of viviparity is not accompanied by a relative increase in maternal abdomen size in lizards. Future work could usefully investigate other lineages of lizards to determine whether our results are generalisable to all lizards.