点纹斑竹鲨晚期胚胎侧线系统的研究

The lateral line system of Chiloscyllium punctatum at the late embryonic stage

摘要:

通过阿利新蓝染色、石蜡切片和扫描电镜，对点纹斑竹鲨晚期胚胎侧线系统的分布、形态和表面结构进行了观察。结果表明，点纹斑竹鲨的侧线系统与多数软骨鱼板鳃类相一致，包括有机械感受功能的侧线管和陷器，以及有电感受功能的罗伦氏壶腹器。侧线管分布呈典型的“七管模式”，其内的管道神经丘位于侧线管内远离体表的一侧，由覆盖细胞、支持细胞和感觉细胞组成。陷器分布于背部两体侧线管之间，单个陷器位于两盾鳞间，深陷在真皮中，由1短管通向表面，管壁不规则，上段由表皮细胞组成，管深40~60 μm。罗伦氏壶腹器由管孔、罗伦管和罗伦瓮3部分组成，呈长颈瓶状，很多罗伦管都较长，从1 mm~50 mm 不等，管壁规则；罗伦瓮由7个罗伦小囊组成，每个小囊直径约50 μm。通过与其他软骨鱼类进行比较，点纹斑竹鲨的侧线系统分布和感受器结构不但印证了软骨鱼类的系统发育关系，同时也与其生活习性相适应。

Abstract:

The distribution pattern and the surface structure of the lateral line system at the late embryonic stage in Chiloscyllium punctatum are examined by using Alcian blue stain, parafin section and SEM. The result reveals that morphological pattern of the lateral line system of Chiloscyllium punctatum is the same as most of the elasmobranch (Hemiscyllidae). The system consists of the mechanoreceptive canal neuromasts and pit organs, and the electroreceptive, Ampullae of Lorenzini organs. The lateral line canals are arranged in a basic sevencanal pattern. The canal neuromasts consist of mantle cells, support cells and sensory hair cells. They are surrounded by light cartilage canal wall and buried under the skin. The Pit organs are similar in compositions as, but smaller in size than, the canal neuromasts. They are standing in line on dorsal of the trunk and between the two sides of the trunk lateral line canals, each organ opens to the skin surface between two scales and through a short tube (about 40~60 μm long) with wall of irregularly arranged epidermal cells. The Ampullae of Lorenzini consists of the pore on the surface of the skin, tubules and ampulla (with sensory cells) in the derm. Most of Lorenzini tubules range from 1-50 mm with wall of regularly arranged epidermal cells; each Lorenzini ampulla is about 50 um in diameter and consists of 7 sacs. The patterns of the lateral line distribution and the structure of the receptors in Chiloscyllium punctatum are congruent with its phylogenetic relationships with others in the Chondrostei. It is also adapted to their habitat preferences.