Bats have the ability to fly without eye application in the darkness. In this study, we aimed to characterize the functional and structural acclimations of the lenses of two common bats with a various lifestyle in the Egyptian environment: the insectivorous bat (IB) (Pipistrellus kuhlii) and Egyptian fruit bat (FB) (Rousettus aegyptiacus). From each species, seven lenses were extracted from adult eyes. The scanning electron microscopic (SEM) and light microscopic examination of the lens were carried out. FB lenses were made up primarily of fiber cells and sheets, which were encapsulated by a thin collagenous capsule and covered by single epithelial layer anteriorly. On the other hand, the IB lens had two poles and was visibly oval shaped. Both lenses had epithelial cells of the same cuboidal form that were subjected to continuous division and differentiation into new fiber cells at the center. SEM revealed that the normal FB lens had regularly organized shells of fiber cells of intact lens fibers which were connected by membrane interdigitations with different shapes mainly ball‐and‐socket junctions through the superficial cortical fiber cells. The IB lens was composed of parallel, evenly spaced fibers with various types of interdigitations between fibers that can be seen and increased close to the middle region revealing tiny bumps along the scrubby portions and sockets and balls in the center of the wide portions. Near the center of both lenses, there were large interlocking paddles with little and lengthy protrusions along their short sides. In conclusion, our study discovered several ultrastructural and structural variations among the investigated species. The detection of specialized membrane interdigitations with different shapes protruding from the lens fiber sheets is considered the most characteristic of the FB lens.Research Highlights FB lens has more organized sheets of fibers parallel to each other than IB lens. Different shapes of interdigitations protruded from the FB lens have been detected. Interlocking paddles, balls, and sockets with tongue‐like fiber flabs are characteristic to FB lens.

中文翻译：

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食虫蝙蝠 (Pipistrellus kuhlii) 和埃及果蝠 (Rousettus aegyptiacus) 晶状体的比较光和扫描电子显微镜研究

蝙蝠具有在黑暗中无需眼睛就能飞行的能力。在这项研究中，我们的目的是描述埃及环境中两种生活方式不同的常见蝙蝠晶状体的功能和结构适应情况：食虫蝙蝠（IB）（库氏海螺）和埃及果蝠（FB）（埃及棕蝠）。从每个物种的成年眼睛中提取了七个晶状体。对透镜进行了扫描电子显微镜（SEM）和光学显微镜检查。FB晶状体主要由纤维细胞和片层组成，它们被薄的胶原蛋白囊包裹，并且前面被单上皮层覆盖。另一方面，IB 透镜有两个极点，并且明显呈椭圆形。两个晶状体都有相同的立方体形式的上皮细胞，这些细胞在中心不断分裂和分化成新的纤维细胞。扫描电镜显示，正常的FB晶状体具有规则组织的完整晶状体纤维的纤维细胞壳，这些纤维细胞通过表面皮质纤维细胞通过不同形状的膜交叉连接（主要是球窝连接）连接。IB 透镜由平行、均匀间隔的纤维组成，纤维之间有各种类型的交叉，可以看到这些交叉并在靠近中间区域的地方增加，显示出沿着毛茸茸的部分的微小凸起以及宽部分中心的插座和球。在两个透镜的中心附近，都有大​​的互锁桨，沿着它们的短边有小而长的突起。总之，我们的研究发现了所研究物种之间的一些超微结构和结构变异。检测从透镜纤维片突出的不同形状的特殊膜交错被认为是 FB 透镜的最大特点。 FB 透镜比 IB 透镜具有更多组织有序且彼此平行的纤维片。 已检测到从 FB 透镜突出的不同形状的叉指。 联锁桨、球和带有舌状纤维片的插座是 FB 透镜的特征。