暗纹东方鲀侧线系统早期形态和生长发育

A Postembryonic Study on the Morphological and Growth Pattern of the Lateral Line System in the Pufferfish Takifugu obscurus

通过光镜和扫描电镜对暗纹东方鲀(Takifugu obscurus)的侧线系统进行形态学及组织学的研究。研究结果首次揭示了暗纹东方鲀侧线系统除了主侧线外还包括辅助侧线和辅助神经丘。主侧线分布主要包括眶上线、眶下线、耳后侧线、下颌线、前鳃盖线、上颞线、背侧线、腹侧线。辅助侧线和辅助神经丘分布主要包括口部辅助侧线、眶下辅助侧线、下颌前辅助侧线、下颌后辅助侧线、眶上后辅助侧线、上颞腹辅助神经丘、上颞背辅助神经丘、前鳃盖后辅助神经丘、背部辅助神经丘、尾部辅助神经丘。暗纹东方鲀侧线器官为接受机械刺激的神经丘,数目上千,神经丘分布在体表的凹槽里,且位于高低不同突起顶端。神经丘由套细胞、支持细胞和感觉毛细胞组成。感觉毛细胞呈圆形排列,并且每个细胞的游离面均有一根动纤毛和几十根静纤毛。据本研究对暗纹东方鲀侧线分布特征和神经丘的生长特征等的观察结果,认为尽管暗纹东方鲀侧线系统没有如其他真骨鱼类的管道系统,但是依然具有两套不同生理机能的机械感受系统,符合"七管模式"的主侧线神经丘与管道神经丘同源,而辅助侧线和辅助神经丘才是真正的表面神经丘。

By using light and scanning electron microscopy,unique characteristics in the morphology,histology,and growth patterns of the lateral line system was observed in the Pufferfish,Takifugu obscures.The lateral line system of T.obscurus is consisted of the main lines and accessory lines（and accessory neuromasts）.The former includes supraorbital,infraorbital,postotic,mandibular,preopercular,and supratemporal lines on the head,and dorsal,and ventral trunk lines on the body.The later includes rostral accessory,infraorbital accessory,mandibular accessory,posteriodorsal mandibular accessory,and posterodoral supraorbital accessory lines,and ventral supratemporal accessory,dorsal supratemporal accessory,posterior preopercular accessory,trunk accessory and caudal accessory neuromasts.There are over one thousand neuromasts,the mechanoreceptive organs,in the lateral line system of T.obscures.They are uniquely located at the top of the individual tubercle,and distribute in the superficial grooves which are arranged according to the above topographic line patterns.Each of the neuromast consists of sensory hair cells,supporting cells and surrounded by mental cells.Sensoryhair cells stay in circular at the centre of the neuromast.Each of them has one kinocilium and dozens of stereocilia on the top.Even though there is no real canal system in the T.obscurus,the patterns of the line distribution and the growth of neuromasts that indicate that the lateral line system in the T.obscurus still have two mechanoreceptive systems such as in other teleoste fishes.The neuromasts in the main lines may be homologues of the canal neuromasts and the neuromasts in the accessory lateral line and accessory neuromasts may be the real superficial neuromasts.