Rodrigues Fernanda M, Sá Fabricio B DE, Languidey Pablo H, Vergara-Parente Jociery E, Guimarães Juliana P
Universidade Federal de Goiás, Rodovia Goiânia-Nova Veneza, Km 8, Campus Samambaia, 74690-900 Goiânia, GO, Brazil.
Universidade Federal Rural de Pernambuco, Departamento de Morfologia e Fisiologia Animal, Laboratório de Oftalmologia Experimental, Rua Dom Medeiros, s/n, Dois Irmãos, 52171-900 Recife, PE, Brazil.
An Acad Bras Cienc. 2022 Dec 5;94(suppl 3):e20211599. doi: 10.1590/0001-3765202220211599. eCollection 2022.
Recent studies showed that vision and hearing in dolphins are mechanisms for perception of the environment, and transmission of information among individuals. Considering that Guiana dolphins (Sotalia guianensis) are distributed in costal regions, and Clymene dolphins (Stenella clymene) are found in oceanic environments, the objective of this study was to compare the morphology of the eyes of these two species, assessing the differences in eye structures in both environments. Five specimens of Sotalia guianensis and four specimens of Stenella clymene were analyzed. All the specimens were found stranded in the northeastern coast of Brazil. Samples were fixated in 10% formaldehyde, dissected, photographed, processed, and analyzed by optical microscopy. The inferior palpebral region of the two species showed a granular layer, subcutaneous lymphoid tissue, and innervation. Morphometric values of the eyelid structures and eye bulb were greater in S. clymene. The cornea showed four layers in S. clymene: anterior epithelium, anterior lamina, stroma, and posterior lamina. The sclera of S. guianensis showed more melanocytes and presence of mechanoreceptors next to the Harderian gland. It is possible to suggest that the geographical distribution of these cetaceans determine their eye morphology, which is an adaptation to the intrinsic characteristics of the aquatic environment.
最近的研究表明，海豚的视觉和听觉是感知环境以及个体间信息传递的机制。鉴于圭亚那海豚（Sotalia guianensis）分布在沿海地区，而 Clymene 海豚（Stenella clymene）生活在海洋环境中，本研究的目的是比较这两个物种眼睛的形态，评估两种环境下眼睛结构的差异。分析了 5 只圭亚那海豚标本和 4 只 Clymene 海豚标本。所有标本均在巴西东北海岸被发现搁浅。样本用 10%甲醛固定，进行解剖、拍照、处理，并通过光学显微镜分析。两个物种的下睑区域均显示出颗粒层、皮下淋巴组织和神经支配。Clymene 海豚的眼睑结构和眼球的形态测量值更大。Clymene 海豚的角膜有四层：前上皮、前板层、基质和后板层。圭亚那海豚的巩膜显示有更多黑素细胞，且在哈德腺附近存在机械感受器。可以推测，这些鲸类动物的地理分布决定了它们的眼睛形态，这是对水生环境固有特征的一种适应。
