Morphological basis of excretory function in Nausitora fusticula(Jeffreys, 1860) (Bivalvia : Teredinidae)

摘要

The function of the excretory system of the teredinid bivalve Nausitora fusticula is discussed on the basis of new information on histology and ultrastructure. The wall of the auricles is lined with podocytes that allow haemolymph ultrafiltration to the pericardial cavity. These podocytes also show apical microvilli with absorptive activity. The primary urine is drained from the pericardial cavity to the afferent ducts by a citiated bulb-like structure. The afferent and efferent ducts together form the kidney body. The afferent duct shows structures related to absorption, excretion and conduction of the urine. The efferent ducts, however, have structures concerned only with urine absorption and conduction.