Micromorphology of the median eminence in the percoid fish, Trichogaster fasciatus (Bloch and Schneider).

The pituitary of Trichogaster fasciatus is devoid of a distinct stalk and is closely attached to the floor of the brain. The third ventricle is in wide communication with the anterior neurohypophysis adjacent to the pars distalis. The subterminal region of the hypothalamus and the anterior neurohypophysis forms the median eminence. Structurally this region can be compared to the median eminence of tetrapods as it is differentiated into ependymal, fibrous and reticular layers. A close morphological contact between the stainable neurosecretory and silver positive axons with the capillary plexus and accumulation of neurosecretory material around the capillary network suggest the presence of an incipient tetrapodan type of median eminence in this species.