Ultrastructure of the Neuro-and Adenohypophysis of the Teleost,Chasmichthys dolichognathus*

Ultrastructure of the Neuro-and Adenohypophysis of the Teleost, Chasmichithys dolichognathus The hypophysis of the gobiid teleost investigated is embedded in the hypothalamus except for its ventral surface. The neurohypophysis constitutes a thin sheet covering the adenohypophysis. The anterior part of the neurohypophysis, which wraps the rostral pars distalis and the most rostral part of the caudal pars distalis, contains neurosecretory axons the most predominant type of which is characterized by granulated vesicles between 70 and 120 nm. in diameter. In the posterior part of the neurohypophysis which covers the main part of the caudal pars distalis and the pars intermedia the most abundant neurosecretory axons contain granulated vesicles between 110 and 170 nm. in diameter. Following discussion of the regional structural differences, the goby neurohypophysis is compared with the median eminence and the posterior lobe of tetrapods.