The aim of this work was to estimate the baseline of the swimming performances of the
red porgy (Pagrus pagrus pagrus), during the critical swimming tests (Ucrit), together with the energetic expenditure at the different of the fish.
In fish, swimming is the most important factor influencing the Darwinian success. It is mainly studied trough prolonged swimming exercises and assessed by mean of the critical swimming test (Ucrit), which represents the maximum aerobic activity a fish could expresses (Plaut, 2001). The Ucrit is strictly linked with the fish physiological condition and, for this reason, it is often used as a welfare indicator. Critical swimming speed allows also to assess fish responses to many kind of stressors (FSBI, 2002) that generally have the effect of reducing the fish swimming capacity. Moreover, the muscular activity is strictly correlated with the oxygen consumption rate, that increases proportionally with the swimming speed,
acting as an index of the activity of the aerobic metabolism (Smit et al., 1971). The energy mobilization follows a pattern in which the amount of oxygen consumption is proportional to the work done during the muscular activity (Beamish, 1978). Aim of this work, is to get insight into the energetic physiology of red porgy, a species included in the IUCN red list and thus requiring particular management measures.