Histophysiology and Histochemical Analysis of the Saccus Vasculosus of Butter Catfish Ompok bimacualtus (Bloch, 1794)

Cellular details including histochemical nature and functional aspects of saccus vasculosus in Ompok bimaculatus (Bloch, 1794)were studied using histological and histochemical techniques. The oval protruded saccus vasculosus situated on the ventral side of the diencephalon behind the pituitary. This circumventricular organ contained a typical large central lumen lined by single stratified epithelium with characteristic coronet cells and supporting cells. Silver stain was adopted for the occurrence and distribution of neurons if any in the epithelium and various regions of the saccus vasculosus. Intensity of glycogen was found to be associated with the coronet cells and blood vessels. Histochemical localization of basic protein and bound lipid were recorded in the cells of saccus epithelial lining as well as in the blood vessels. Coronet cells perhaps involved in secretory as well as sensory function of the fish concerned.