[Reactions of the pinealocytes on the scorpionfish, Scorpaena porcus, to ionic equilibrium disorders]

Morpho-functional changes in scorpionfish pinealocytes have been observed during an increase in potassium sodium or magnesium content of the sea water. These changes include the increase in the height and the diameter of the nuclei of pinealocytes, the increase being followed by apocrynic secretion in the cells. It is suggested that the pineal organ of the scorpionfish is involved in the reaction of the organism to changes in the ionic balance of the internal milieu.