Henry L. Heyl

Fine structure of the corpuscles of Stannius of Atlantic salmon during the freshwater spawning journey

Abstract Corpuscles of Stannius (CS) from Atlantic salmon ( Salmo salar L.) in various stages of their freshwater spawning journey were examined by light and electron microscopy. The ultrastructural features of the typical columnar parenchymal cell were characteristic of a cell engaged in protein secretion, namely, a large vescular nucleus with dispersed chromatin, numerous secretory franules, a well-developed Golgi complex and an extensive rough-surfaced endoplasmic reticulum. Regressive changes, typified by the presence of clusters of degenerative parenchymal cells, were observed in the CS of all fish examined. There was a direct relation between the extent of glandular regression and the length of time the fish had been in fresh water. These observations support the presently held view that the CS are involved in the production of a proteinaceous hormone active in mineral exeretion, particularly in hypersaline environments.

Changes in the corpuscle of Stannius during the spawning journey of Atlantic salmon (Salmo salar)

Abstract In an effort to clarify the function of the corpuscle of Stannius in Atlantic salmon ( Salmo salar ), histological studies were made of specimens from Canadian fish taken at various stages in the spawning journey. The general architecture and cell types of the corpuscle changed in several ways; these were more closely related to time in fresh water than to gonadal development. An anatomical unit composed of ganglion cells, nerves, and thick-walled blood vessels was consistently noted between the corpuscle and adjacent renal tissue. The relation of these observations to the overall function of the teleostean kidney with its several mechanisms for homeostatic control of electrolytes and steroid activity is briefly discussed.