六种鲽形目鱼类无眼侧头部皮肤形态特征与功能探讨

本研究采用扫描电镜方法首次对半滑舌鳎、大菱鲆等6种鲽形目鱼类无眼侧头部皮肤形态结构进行观察比较,以期获得与摄食行为等生态习性相关的新发现。结果显示,半滑舌鳎和塞内加尔鳎的无眼侧头部皮肤存在大量游离神经丘,但其形态特征存在差异。半滑舌鳎皮肤表面的游离神经丘类似于乳头状突起,突起上有表皮细胞形成的微脊,多个为一簇,很少单独存在,呈无规则排列;而塞内加尔鳎的游离神经丘直接裸露在皮肤表面,呈线性排列在肉芽状皮肤突起的下方。星突江鲽的头部无眼侧皮肤表面零散分布着多个为一簇的游离神经丘,形状类似于半滑舌鳎的乳头状游离神经丘。大菱鲆、黄盖鲽和条斑星鲽的头部无眼侧皮肤表面未发现游离神经丘等特殊结构,但其表面均凹凸不平。研究推测鲽形目鱼类头部无眼侧皮肤形态特征与其摄食习性密切相关;其头部无眼侧游离神经丘的分布特征与种群分类存在一定的相关性,可为物种的分类提供一定依据。

Morphological characteristics and functional investigation of the abocular side skins on head of six pleuronectiformes fishes

In this study, the morphologies of the abocular side skins on head of six pleuronectiformes fish were investigated by scanning electron microscopy (SEM). The results showed that a large number of free neuromasts were found on the abocular side skins of Cynoglossus semilaevis and Solea senegalensis with more occurring around the anterior nares and the tips. The free neuromasts in C. semilaevis look like papillae, are covered by many skin wrinkles consisted of epidermis cells and generally appear in groups with random arrangement. However, the free neuromasts of S. senegalensis skins, exposed on the surface with a linear arrangement, lie under the bud-like epidermis. A small amount of neuromasts scatter on head skins of Platichthys stellatus, whose morphologies were similar to those of C. semilaevis. Except orifices of mucus secretion, there were no special structures examined on the skins of abocular sides of Scophthalmus maximus, Limanda yokohamae and Verasper moseri. According to the differences on organization and distribution of free neuromasts, it is inferred that morphological characteristics of the abocular side skins in pleuronectiformes could be closely related to their feeding behaviors. The distribution characters of free neuromasts on the abocular side skins can provide a certain support for species classification of pleuronectiformes.