Renal mucous production in Australian freshwater plotosid and ariid catfishes.

This study reports the presence of large mucous cells lining the large renal collecting ducts and opisthonephric ducts of the Australian freshwater catfishes Tandanus tandanus and Tandanus tropicanus. Histologic examination of the renal tissue from four other species of Australian freshwater catfishes suggests that this feature is unique to the two species of Tandanus studied. The potential functions of renal mucous secretion in T. tandanus and T. tropicanus are discussed.