Quinzio Silvia I, Reiss John O
Instituto de Bio y GeoCiencias del NOA (IBIGEO), Centro Científico Tecnológico CONICET ̶ Salta. 9 de Julio 14. 4405. Rosario de Lerma, Salta, Argentina.
Department of Biological Sciences, Humboldt State University, Arcata, California.
J Morphol. 2018 Jan;279(1):37-49. doi: 10.1002/jmor.20751. Epub 2017 Sep 26.
The aquatic-to-terrestrial shift in the life cycle of most anurans suggests that the differences between the larval and adult morphology of the nose are required for sensory function in two media with different physical characteristics. However, a better controlled test of specialization to medium is to compare adult stages of terrestrial frogs with those that remain fully aquatic as adults. The Ceratophryidae is a monophyletic group of neotropical frogs whose diversification from a common terrestrial ancestor gave rise to both terrestrial (Ceratophrys, Chacophrys) and aquatic (Lepidobatrachus) adults. So, ceratophryids represent an excellent model to analyze the morphology and possible changes related to a secondary aquatic life. We describe the histomorphology of the nose during the ontogeny of the Ceratophryidae, paying particular attention to the condition in adult stages of the recessus olfactorius (a small area of olfactory epithelium that appears to be used for aquatic olfaction) and the eminentia olfactoria (a raised ridge on the floor of the principal cavity correlated with terrestrial olfaction). The species examined (Ceratophrys cranwelli, Chacophrys pierottii, Lepidobatrachus laevis, and L. llanensis) share a common larval olfactory organ composed by the principal cavity, the vomeronasal organ and the lateral appendix. At postmetamorphic stages, ceratophryids present a common morphology of the nose with the principal, middle, and inferior cavities with characteristics similar to other neobatrachians at the end of metamorphosis. However, in advanced adult stages, Lepidobatrachus laevis presents a recessus olfactorius with a heightened (peramorphic) development and a rudimentary (paedomorphic) eminentia olfactoria. Thus, the adult nose in Lepidobatrachus laevis arises from a common developmental 'terrestrial' pathway up to postmetamorphic stages, when its ontogeny leads to a distinctive morphology related to the evolutionarily derived, secondarily aquatic life of adults of this lineage.
大多数无尾两栖动物生命周期中从水生到陆生的转变表明，鼻子在幼体和成年形态上的差异是在两种具有不同物理特性的介质中发挥感觉功能所必需的。然而，对适应介质的专业化进行更好控制的测试是将陆生青蛙的成年阶段与成年后仍完全水生的青蛙进行比较。角蛙科是新热带界青蛙的一个单系类群，它们从一个共同的陆生祖先分化而来，产生了陆生（角蛙属、叉角蛙属）和水生（的的喀喀湖角蛙属）的成年个体。因此，角蛙科代表了一个分析与次生水生生活相关的形态学及可能变化的优秀模型。我们描述了角蛙科个体发育过程中鼻子的组织形态学，特别关注嗅隐窝（一个似乎用于水生嗅觉的小面积嗅觉上皮区域）和嗅隆突（主腔内底部与陆生嗅觉相关的隆起嵴）在成年阶段的状况。所研究的物种（克兰韦尔角蛙、皮氏叉角蛙、光滑的的喀喀湖角蛙和利亚内斯的的喀喀湖角蛙）具有一个由主腔、犁鼻器和侧附件组成的共同幼体嗅觉器官。在变态后阶段，角蛙科呈现出一种共同的鼻子形态，具有主腔、中腔和下腔，其特征与其他新蛙亚目动物在变态末期相似。然而，在成年后期，光滑的的喀喀湖角蛙的嗅隐窝发育增强（形态超常），嗅隆突退化（幼态持续）。因此，光滑的的喀喀湖角蛙的成年鼻子在变态后阶段之前源于一条共同的发育“陆生”途径，之后其个体发育导致了一种与该谱系成年个体进化而来的次生水生生活相关的独特形态。
