Anatomy of finfish and shellfish

Unit 9 - Endocrine system

9.2.10. Corpuscles of Stannius
The Corpuscles of Stannius, which occur in the kidney of many actinopterygian fishes, have often been viewed as potentially endocrine. these arise as many (40 or) more)diverticulate from the nephric ducts in the anterior part of the opisthonephros (segments 9 to 12) of Amia and Lepisosteus or, in teleosts, as a few or even a single pair of diverticulae in the posterior region of the kidney.These are islands of eosinophilic granular cells located in paired organs on the ventral surface of the kidney. This organ secretes a protein called hypocalcin (teleocalcin) that acts with calcitonin to regulate calcium metabolism. The parathyroid glands are absent in the sharks and in the actinopterygian fishes; their function is taken over by other endocrine organs (Corpuscles of Stannius).