The isolated open-circuited shanny skin exhibited a net chloride efflux of 2.91 μmol h−1. The transepithelial potential was 12 mV (inside + ve). Short circuit current was 60 μA cm2 and transepithelial resistance was 225 Ω cm2. When either ouabain or furosemide was added to the inside, or amiloride or 4-acetamido-4′-isothiocyanatostibene-2,2′-disulphonic acid (SITS) was added to the outside, the transepithelial potential and short-circuit current were reduced. The results are discussed and a model is presented that describes the possible mechanism for chloride transport across shanny skin.