Before metamorphosis, almost all anuran tadpoles are omnivores. Larval carnivory occurs in some species and, it is associated with distinctive morphotypes. Obligatory carnivorous tadpoles exhibit structural changes in the gastrointestinal tract compared to larvae that are predominately omnivores. The most distinctive feature of the anuran family Ceratophyridae (three genera) overall is the enormous gape of adults. This feature increases their ability to capture extremely large and active prey. The larvae of Ceratophyrid genera are remarkably distinct from each other and carnivory has diversified in a manner unseen in other anurans. The larvae of one genus, Lepidobatrachus, has a massive gape like the adult. Herein, we report on larval developmental variation, diet, gross morphology of the gastrointestinal tract, and histology of the cranial segment of the gut before, during and after metamorphosis in larval series for the following ceratophryid species: Chacophrys pierottii, Ceratophrys cranwelli, Lepidobatrachus laevis and Lepidobatrachus llanensis. We described patterns of larval development with variation in growth with consequence to the final size at the end of metamorphosis. These patterns seem to be influenced by food quantity/quality, and most predominant by animal protein. Prey items found in pre and post-metamorphic Lepidobatrachus spp. are similar. Tadpoles of Ceratophrys and Chacophrys (and other anurans) share a short cranial segment of the gut with an internal glandular, mucous secreting epithelium, a double coiled intestine and the sequence of metamorphic changes (tract is empty, the stomach differentiates and the intestine shortens abruptly). In contrast, Lepidobatrachus tadpoles have a true stomach that acquires thickness and increased glandular complexity through development. As larvae they have a short intestine without double coils, and the absence of intestine shortening during metamorphosis. The larval development of the gastrointestinal tract of Lepidobatrachus is unique compared with that of other free-living anuran larvae. An abrupt metamorphic transformation is missing and most of the adult structural features start to differentiate gradually at the beginning of larval stages.

中文翻译：

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饮食和肠形态的进化和发育方面的考虑，在鱼（Anura）中。

在变态之前，几乎所有的无头t都是杂食性的。幼虫食肉动物在某些物种中发生，并且与独特的形态型有关。与主要杂食性的幼虫相比，强制性食肉性exhibit在胃肠道中表现出结构变化。总的来说，无性家族的角藻科（3属）最显着的特征是成年的巨大鼻孔。此功能提高了它们捕获大型活跃猎物的能力。Ceratophyrid属的幼虫彼此明显不同，食肉动物以其他无脊椎动物中未见的方式多样化。一个属的鳞翅目幼虫（Lepidobatrachus）的幼虫与成虫一样具有巨大的毛孔。在此，我们报告幼虫的发育变化，饮食，胃肠道的总体形态，在以下幼虫系列的幼虫系列变态之前，期间和之后的肠道颅节的组织学和组织学：Chacophrys pierottii，Ceratophrys cranwelli，Lepidobatrachus laevis和Lepidobatrachus llanensis。我们描述了幼虫发育的模式，其生长变化导致变态结束时的最终大小。这些模式似乎受食物数量/质量的影响，并且主要受动物蛋白的影响。在变态的鳞翅目Lepidobatrachus spp中发现的猎物。相似。rat足动物和Cha足动物（和其他无核动物）的share共有短的颅骨节段，内部有腺体，粘液分泌的上皮，双螺旋状肠和变态序列（尿道是空的，胃分化，肠突然缩短）。相反，鳞翅目Le具有真正的胃，可通过发育获得厚度并增加腺的复杂性。作为幼虫，它们的肠道短而没有双螺旋，并且在变态期间没有肠道缩短。与其他自由生活的无尾无核幼虫相比，鳞翅目小肠胃肠道的幼虫发育是独特的。突变的突变消失了，大多数成虫的结构特征在幼虫开始时就开始逐渐分化。并且在变态过程中没有肠道缩短。与其他自由生活的无尾无核幼虫相比，鳞翅目小肠胃肠道的幼虫发育是独特的。突变的突变消失了，大多数成虫的结构特征在幼虫开始时就开始逐渐分化。并且在变态过程中没有肠道缩短。与其他自由生活的无尾无核幼虫相比，鳞翅目小肠胃肠道的幼虫发育是独特的。突变的突变消失了，大多数成虫的结构特征在幼虫开始时就开始逐渐分化。