Eels from Lake Balaton are unique because they do not undergo the silvering process and do not migrate. The question is whether these eels, despite such particularities, retain their ability to cope with migration constraints, usually high pressure. To ascertain this, eels were exposed for 3 days to 10.1 MPa of hydrostatic pressure (HP) and the effects of this on aerobic metabolism were evaluated by measuring oxygen consumption (MO2), Cytochrome Oxydase activity (COX) and energetic nucleotide contents in red and white muscles. The results show that Balaton eels survive HP. However, 3 days under pressure induces an alteration in aerobic metabolism. Moreover, when only muscle fibres are exposed to HP, there is a significant decrease in maximal aerobic capacities (-20%). The results are discussed in terms of the ability of these eels to migrate, bearing in mind that this activity represents a high percentage of maximal aerobic capacity when compared with other populations.