Abstract 1. 1. The oxygen consumption of excised skin and the normal cutaneous oxygen uptake by the skin in situ from the external medium were investigated in six freshwater teleosts in normoxic freshwater: crucian carp ( Carassius carassius L.), yellow perch ( Perca fluviatilis L.), northern pike ( Esox Indus L.), brook trout ( Salvelinus fontinalis M.), brown trout ( Salmo trutta fario L.) and the catfish ( Ictalurus melas R.). 2. 2. Cutaneous oxygen uptake from the external medium is equal to (crucian carp, brook trout, brown trout) or smaller than (perch, pike) cutaneous oxygen consumption. Consequently the skin in these five fish is not an oxygen exchanger for the benefit of other organs. 3. 3. In catfish, the skin may be considered although to a small extent (about 5% of oxygen requirement) as a respiratory organ.