Mitta Swati, Ojha Jagdish, Mittal Ajay
Skin Physiology Laboratory, Centre of Advance Study, Department of Zoology, Banaras Hindu University, Varanasi, India.
Eur J Morphol. 2002 Jul;40(3):161-9. doi: 10.1076/ejom.40.3.161.16685.
The surface architecture of the structures associated with the lips of a hill stream fish Garra lamta was examined by scanning electron microscopy. In this teleost, the lips are inconspicuous and associated with prominent horny jaw sheaths. Furthermore, the upper and lower lips are associated with a greatly enlarged rostral cap and an adhesive pad, respectively. The rostral cap has a proximal mucogenic region and a distal keratinized region. The adhesive pad is differentiated into central mucogenic and peripheral keratinized regions. At the mucogenic regions of the rostral cap and the adhesive pad, the surface of the epithelial cells is characterised by well developed microridges, which reflect their high secretory activity. The mucus may lubricate the surface and protect the epithelia from abrasions at these regions, which are likely to be subjected to wear and tear during frequent friction and adhesion of the fish to the substrate. Taste buds may help the fish to locate food and trigger a 'pick-up' reflex. The epithelial cells at the surface of the keratinized regions of the rostral cap and the adhesive pad are modified as clusters of spine like unculi, which may assist the fish in its firm anchorage to the substrate. The epithelial cells at the surface of the horny jaw sheaths are modified as polygonal unculi, each appears much like a tooth that has a characteristic sharp edge at the margin. These may be regarded as an adaptation to browsing or scraping food materials from the substrate.
通过扫描电子显微镜对山溪鱼类细纹墨头鱼（Garra lamta）唇部相关结构的表面构造进行了研究。在这种硬骨鱼中，唇部并不明显，且与突出的角质颌鞘相关联。此外，上唇和下唇分别与一个大幅扩大的吻帽和一个吸盘相关联。吻帽有一个近端的黏液生成区域和一个远端的角质化区域。吸盘分化为中央黏液生成区域和周边角质化区域。在吻帽和吸盘的黏液生成区域，上皮细胞表面的特征是有发育良好的微嵴，这反映了它们较高的分泌活性。黏液可能会润滑这些区域的表面，并保护上皮免受磨损，在鱼类频繁摩擦和附着于基质的过程中，这些区域很可能会受到磨损。味蕾可能有助于鱼类定位食物并触发“摄取”反射。吻帽和吸盘角质化区域表面的上皮细胞被修饰成簇状的刺状小丘，这可能有助于鱼类牢固地附着在基质上。角质颌鞘表面的上皮细胞被修饰成多边形小丘，每个小丘看起来很像一颗在边缘有特征性锋利边缘的牙齿。这些可以被视为一种适应，用于从基质上啃食或刮取食物材料。
