Pituitary Glands

• The pituitary gland occupies the same central part in the endocrine signaling system of fish that it has in mammals.
• The pituitary gland is located below the diencephalon (hypothalamus), behind the optic chiasma and anterior to saccus vasculosus, and is attached to the diencephalon by a stalk or infundibulum.
• The size of infundibulum varies according to the species. Usually in cyclostomes it is smaller but increases in bony fishes, with prominence in groove or depression of parasphenoid bone receiving the gland.
• There is no sella turcica comparable to that found in mammals in Xiphophorus.
• The short, thick- walled, hollow infundibular stalk contains a lumen, which continues with the third ventricle.