细尾高原鳅和东方高原鳅不同组织器官黑色素的分布和比较

采用组织学方法比较研究细尾高原鳅和东方高原鳅组织器官的黑色素分布特征。结果显示: 两种高原鳅头部皮肤、背部皮肤、体侧皮肤、腹膜肾脏层、脊髓腔壁层、腹膜壁层、围心腔壁层、脑颅腔壁层和眼睛均分布有黑色素;腹部皮肤、肝脏浆膜、脾脏被膜和性腺被膜未发现黑色素。皮肤中黑色素分布在真皮层和皮下组织,其他组织器官中黑色素分布在内膜层或壁层。黑色素主要分布在背侧,体侧则分布稀疏,呈现对称分布。背部和体侧皮肤有斑块处较无斑块处黑色素数量多,分布密集;无斑块处仅是部分聚集,或形成间断分布的黑色素块。同一种高原鳅不同组织器官黑色素分布不同,分布面积百分比和黑色素层厚度有显著性差异,但两种高原鳅同一组织器官黑色素分布特征相似。两种高原鳅组织器官中黑色素的分布与其接受的紫外辐射强度有关,是对高原强紫外辐射环境的适应。

Distribution and comparison of melanin in different tissues and organs of Triplophysa stenura and T. orientalis

We examined the distribution characteristics of melanin in different tissues and organs of Triplophysa stenura and T. orientalis by using histological method. The results showed that melanin was distributed in the head skin, dorsal skin, lateral skin, peritoneal kidney layer, spinal cord cavity wall, peritoneal wall layer, pericardial cavity wall, neurocranial cavity wall and eyes of both Triplophysa species. Melanin was not found in the abdomen skin, liver chorion, gonad capsule and spleen capsule. Melanin was distributed in the dermis layer and subcutaneous layer in the skin, and in the endothelial layer or wall layer in other tissues and organs. Melanin was mainly distributed on the back, with sparse and symmetrical distribution on both sides of the body. Melanin was more abundant and densely distributed on the dorsal and lateral skin with stripes than areas without stripes. Melanin in the no stripes skin was only partially aggregated or formed intermittently distributed melanin patches. The distribution of melanin in different tissues and organs of the same Triplophysa species was different, and the percentage of distribution area and thickness of melanin layer were significantly different. However, the distribution characteristics of melanin in the same tissues and organs were similar in two Triplophysa species. The distribution of melanin in the tissues and organs of both species were related to the intensity of ultraviolet radiation they received, which was an adaptation to the intense ultraviolet radiation environment of the plateau.