Comparative analysis of the integument of different tree frog species from Ololygon and Scinax genera (Anura: Hylidae)

ABSTRACT The integuments of ten treefrog species of two genera from Scinaxnae - O. angrensis (Lutz, 1973), O. flavoguttata (Lutz & Lutz, 1939), O. humilis (Lutz & Lutz, 1954), O. perpusilla (Lutz & Lutz, 1939), O. v-signata (Lutz, 1968), Scinax hayii (Barbour, 1909), S. similis (Cochran, 1952), O. trapicheroi (Lutz & Lutz, 1954) and S. x-signatus (Spix, 1824) - were investigated using conventional and histochemical techniques of light microscopy, and polarized light microscopy. All integuments showed the basic structure of the anuran integument. Moreover, the secretory portions of exocrine glands, such as serous merocrine and apocrine glands, were found to be restricted to the spongious dermis. Lipid content occurred together with the heterogeneous secretory material of the glands with an apocrine secretion mechanism. In addition, clusters of these apocrine glands were present in the ventrolateral integument of some species. Melanophores were also visualized in all examined hylids. However, the occurrence of iridophores, detected through polarized light microscopy, varied according to the species. The Eberth-Katschenko layer occurred in the dorsal integument from both genera, but it was only present in the ventral integument of O. albicans, O. angrensis, O. flavoguttata, O. perpusilla and O. v-signata. Although the integument of all treefrogs showed the same basic structure, some characteristics were genus-specific; however, these features alone may not be used to distinguish both genera.

摘要 本研究采用光学显微镜常规组织学技术、组织化学方法及偏光显微镜技术，对采自饰纹蛙亚科（Scinaxinae）2个属的10种树蛙物种的被皮组织开展了观察分析，所涉物种包括：安氏卵齿蟾（O. angrensis，Lutz, 1973）、黄斑卵齿蟾（O. flavoguttata，Lutz & Lutz, 1939）、矮小卵齿蟾（O. humilis，Lutz & Lutz, 1954）、细斑卵齿蟾（O. perpusilla，Lutz & Lutz, 1939）、V纹卵齿蟾（O. v-signata，Lutz, 1968）、海伊饰纹蛙（Scinax hayii，Barbour, 1909）、相似饰纹蛙（S. similis，Cochran, 1952）、特拉皮切罗卵齿蟾（O. trapicheroi，Lutz & Lutz, 1954）以及X纹饰纹蛙（S. x-signatus，Spix, 1824）。所有受试物种的被皮均具备无尾两栖类被皮的基础结构。此外，外分泌腺的分泌部（如浆液性局部分泌腺与顶浆分泌腺）均局限分布于海绵状真皮层内。具备顶浆分泌机制的腺体，其异质性分泌物质中均伴随脂质成分。此外，部分物种的腹外侧被皮中可见此类顶浆分泌腺聚集形成的腺簇。所有受试雨蛙科物种的被皮中均检出黑素细胞，但通过偏光显微镜检测到的虹彩细胞的分布情况因物种不同存在差异。埃伯斯-卡申科层（Eberth-Katschenko layer）在两个属物种的背侧被皮中均有分布，但仅见于白头卵齿蟾（O. albicans）、安氏卵齿蟾（O. angrensis）、黄斑卵齿蟾（O. flavoguttata）、细斑卵齿蟾（O. perpusilla）及V纹卵齿蟾（O. v-signata）的腹侧被皮中。尽管所有树蛙的被皮均具有相同的基础结构，部分特征呈现属特异性，但仅依靠此类特征不足以区分这两个属。