The kidney of the prussian carp, Carassius auratus gibelio (Cyprinidae). III. Glycogen-rich cells in the distal segment of nephronic tubule.

Glycogen may be present in considerable amount in the distal segment of the nephronic tubule of a teleost freshwater fish, as revealed by light- and electron-microscopical observation. Adaptation of Crassiss auratus gibelio to increased salinity causes alterations of the cell fine structure (e.g. mitochondria and baso-lateral infoldings) but apparently does not influence deposition of glycogen. However glycogen storage is directly controlled by environmental temperature and may be part of an annual rhythm in carbohydrate metabolism.