RT Journal Article SR Electronic T1 Individual variation and repeatability in aerobic and anaerobic swimming performance of European sea bass, Dicentrarchus labrax JF The Journal of Experimental Biology JO J. Exp. Biol. FD The Company of Biologists Ltd SP 26 OP 32 DO 10.1242/jeb.032136 VO 213 IS 1 A1 Marras, S. A1 Claireaux, G. A1 McKenzie, D. J. A1 Nelson, J. A. YR 2010 UL http://jeb.biologists.org/content/213/1/26.abstract AB Studies of inter-individual variation in fish swimming performance may provide insight into how selection has influenced diversity in phenotypic traits. We investigated individual variation and short-term repeatability of individual swimming performance by wild European sea bass in a constant acceleration test (CAT). Fish were challenged with four consecutive CATs with 5 min rest between trials. We measured maximum anaerobic speed at exhaustion (UCAT), gait transition speed from steady aerobic to unsteady anaerobic swimming (Ugt), routine metabolic rate (RMR), post-CAT maximum metabolic rate (MMR), aerobic scope and recovery time from the CATs. Fish achieved significantly higher speeds during the first CAT (UCAT=170 cm s–1), and had much more inter-individual variation in performance (coefficient of variation, CV=18.43%) than in the subsequent three tests (UCAT=134 cm s–1; CV=7.3%), which were very repeatable among individuals. The individual variation in UCAT in the first trial could be accounted for almost exclusively by variation in anaerobic burst-and-coast performance beyond Ugt. The Ugt itself varied substantially between individuals (CV=11.4%), but was significantly repeatable across all four trials. Individual RMR and MMR varied considerably, but the rank order of post-CAT MMR was highly repeatable. Recovery rate from the four CATs was highly variable and correlated positively with the first UCAT (longer recovery for higher speeds) but negatively with RMR and aerobic scope (shorter recovery for higher RMR and aerobic scope). This large variation in individual performance coupled with the strong correlations between some of the studied variables may reflect divergent selection favouring alternative strategies for foraging and avoiding predation. CATconstant acceleration testCVcoefficient of variationEPOCexcess post-exercise oxygen consumptionICCintraclass correlation coefficientKCCKendall concordance coefficientMMRmaximum metabolic rateoxygen consumptionPCrphosphocreatineRMRroutine metabolic rateTBAtail beat amplitudeTBFtail beat frequencyUCATfinal water velocity attained in the constant acceleration testUcritcritical swimming speedUgtgait transition speed