RESPIRATORY COST OF SWIMMING IN LARVAL AND JUVENILE CYPRINIDS

摘要: The relationship between swimming speed and respiration rate for larvae juveniles (1.5-600 mg fresh mass) of two cyprinid species, Chalcalburnus chalcoides Rutilus rutilus , was measured in a flow-tunnel at 20°C. 1. 1. A special tunnel respirometer with small volume fast response had to be constructed cope the methodological difficulties encountered larvae. 2. 2. oxygen uptake increased quadratically if debt incurred highest speeds included calculations. maximum sustainable over 2min were 6–8 lengths s−1; critical marking onset anaerobic processes only 10–15 % lower. Energetics performance similar both species. cost transport much higher than adult fish decreased rapidly during growth. 3. 3. Standard routine metabolic rates scaled an allometry M −0.23, active −0.15, where is body mass grams. In smallest larvae, however, standard nearly independent mass. Their 80 μmolO2 h−1 g−1 twice as high those adults. 4. 4. scope activity on absolute scale, but not when expressed factorial scope, since also high. For same reason, accounted less 25 energy budget, despite transport. 5. 5. data are discussed respect changing pattern ontogeny, shift from cutaneous branchial involved.