Brizzi Rossana, Delfino Giovanni, Pellegrini Roberta
Department of Animal Biology and Genetics, University of Florence, Firenze, Italy.
J Morphol. 2002 Dec;254(3):328-41. doi: 10.1002/jmor.10039.
A structural and ultrastructural study was carried out on the cutaneous glands in some species of Rana (R. dalmatina, R. iberica, R. italica, R. "esculenta," and R. perezi), giving particular attention to the mucous secretory units. Two different types of mucous glands occur in R. dalmatina, R. iberica, and R. italica. Besides the ordinary mucous units, which are randomly distributed over the body surface in both males and females, a further population of mucous glands was observed on the male dorsal skin. The latter is recognizable by the peculiar morphology of the epithelial cells and some characteristics of the secretory product. Specialized mucous glands are absent in both sexes of R. "esculenta" and R. perezi. The possible adaptive role of the specialized mucous glands is discussed in light of the absence of vocal sacs in males of R. dalmatina, R. iberica, and R. italica. Chemosignals released by sexually dimorphic mucous units may replace vocal communication during the breeding season and so play an important role in female attraction and/or territorial announcement. The morphology and possible function of the specialized mucous glands in the three species of Rana are compared with the breeding glands of other frogs and with the hedonic glands of some urodeles (Salamandridae and Plethodontidae), which are known to produce pheromonal substances during courtship.
对某些蛙属物种（黑斑蛙、伊比利亚蛙、意大利林蛙、食用蛙和佩氏蛙）的皮肤腺体进行了结构和超微结构研究，特别关注了黏液分泌单位。在黑斑蛙、伊比利亚蛙和意大利林蛙中存在两种不同类型的黏液腺。除了普通的黏液单位，其在雄性和雌性的体表均随机分布外，在雄性背部皮肤还观察到了另一群黏液腺。后者可通过上皮细胞的特殊形态和分泌产物的一些特征来识别。食用蛙和佩氏蛙的两性均不存在特化的黏液腺。鉴于黑斑蛙、伊比利亚蛙和意大利林蛙的雄性没有声囊，讨论了特化黏液腺可能的适应性作用。两性异形的黏液单位释放的化学信号可能在繁殖季节替代声音交流，从而在吸引雌性和/或宣告领地方面发挥重要作用。将这三种蛙属物种中特化黏液腺的形态和可能功能与其他蛙类的繁殖腺体以及一些有尾目动物（蝾螈科和无肺螈科）的享乐腺进行了比较，已知这些腺体在求偶期间会产生信息素物质。
