版纳鱼螈侧线系统的结构

Structure of lateral line system of the Yunnan caecilian Ichthyophis bannanica

版纳鱼螈(Ichthyophis bannanica)是我国无足目的仅有代表,应用光镜和扫描电镜对版纳鱼螈的侧线系统进行形态学和组织学观察的研究表明:版纳鱼螈幼体表皮中的侧线器官有接受机械刺激的神经丘和电接受壶腹器官两种,神经丘包括表面神经丘和陷神经丘。侧线分布主要包括:头部的鼻侧线、眶上线、眶下线、眶后线、口侧线、下颌线、咽侧线、鳃孔上线和身体上的背侧线。侧线器官的分布密度、大小和凹陷深度明显与周围表皮的厚度和不同部位有关。幼体的侧线器官退化与鳃孔的退化同步,亚成体以后不保留侧线系统。版纳鱼螈的侧线分布和器官结构与其它无足类的大致相似。

Light and scanning electron microscopy were used to study the morphology and histology of lateral line system in the Yurman caecilian Ichthyophis bannanica. The lateral line organs in Ichthyophis bannanica included mechanoreceptive neuromasts and electroreceptive ampullary organs. Neurnmasts included surface neuromasts and pit organs. Distinct series on head region included the nasal, supraorbital, infraorbital, postorbital, oral, mandibular, gular, supraspiracular series and pair of dorsal line on the body. The density, size, sunk depth of the lateral line organs directly correlated with surrounding epidermal height and regions. In larval, the retrogression of the lateral line organs was simultaneous with the retrogression of the spiracular. Juveniles did not retain the system. The distribution pattern and organ structure of the lateral line system in Ichthyophis bannanica was similar to that of the other caecilians, the only noticeable difference involves the distribution of the organs in the supraorbital and infraorbital series .