The morphology of the kidney of the atlantic hagfish, Myxine glutinosa (L.)

Abstract The kidney of the Atlantic hagfish, Myxine glutinosa , consists of large, paired, segmentally arranged renal corpuscles connected to the archinephric ducts by short tubules. The blood supply to the kidneys is arterial in origin; there is no renal portal system. Each renal corpuscle is supplied by one afferent arteriole and drained by several efferent vessels which in turn supply the tubules and archinephric ducts. Irregularly spaced renal veins drain blood from the ducts into the posterior cardinal veins. The capillaries of the multilobed glomeruli are lined by thick endothelial cells which are rarely fenestrated. These are coated by the short pedicels of the podocytes of the visceral layer of Bowman's capsule. The mesangium is well developed between the endothelium and the glomerular basal lamina. The epithelial cells of all regions of the tubules and archinephric ducts are characterized by a brush border, a complex system of lateral interdigitations, and a paucity of basal infoldings. Pits, vesicles, large vacuoles, and single membrane‐limited inclusion bodies (lysosomes?) are abundant in the apical cytoplasm. It is suggested that these cells are specialized for the reabsorption of materials.