鲶鱼（Parasilurus asotus）小窝器官胚胎后发育的定量研究

鲶鱼的小窝器官(电感觉器官)、其壶和感觉毛细胞的数量在胚胎后有很大增长,新的器官在一定时期内大量发生,单个器官内的壶和感觉毛细胞的数量则持续增加,器官形态有较大变化。本文统计了不同体长的鲶鱼三者的数量变化。实验表明,器官、壶和毛细胞可分别从2.5厘米体长时的1400、1400和8400增加到55厘米体长时的2.5万、20万和120万。这种数量的增长,特别是感觉毛细胞在胚胎后的增长机制和发生条件是值得注意的。本文研究了小窝器官的神经支配模式。

ON POSTEMBRYONIC CHANGES AND MORPHOMETRY IN THE PERIPHERAL ELECTROSENSORY SYSTEM OF A CATFISH

The organization of the peripheral electrosensory system and populations of small pit organ, ampulla and sensory hair cell were studied by silver-stained whole mounts of skin and H. E. in a size-graded series of catfish (Parasilurus asotus).Small pit organ is one of electrosensory organs which occurs on surface area of skin of the catfish. Small pit organ of small individual has only one ampulla and that of large one may has 16 ampullae or more. New small pit organ also appear with growth of fish. The mean number of hair cells per ampulla is about 6 and remains constant in different size. As the increase of organ and ampulla, hair cells added greatly. The populations of organ, ampulla and hair cell increase postembryonically from about 1,400, 1,400 and 8,400 (L = 2.5cm) to more than 25,000, 200,000 and 1 200,000 (L=55cm) respectively.The large size of this hair cell population suggests a high biological importance of electrosensory system in the fish and the addition of the hair cell may be involved in sensibility improvement to electric current. It is notable since little or no addition of new neural elements occurs postembryonically in the central nervous system of mammals and espencially in the inner ear of human being. The phenomenon of receptor cell addition raises a multitude of questions about the factors controlling cell addition.