UMR 5554, Institut des Sciences de l'Evolution de Montpellier, Université de Montpellier 2, Station Méditerranéenne de l'Environnement Littoral, 2 Rue des Chantiers, F-34200 Sète, France.
J Exp Biol. 2011 Sep 15;214(Pt 18):3102-10. doi: 10.1242/jeb.056648.
Inter-individual variation in physiological performance traits, which is stable over time, can be of potential ecological and evolutionary significance. The fish escape response is interesting in this regard because it is a performance trait for which inter-individual variation may determine individual survival. The temporal stability of such variation is, however, largely unexplored. We quantified individual variation of various components of the escape response in a population of European sea bass (Dicentrarchus labrax), considering both non-locomotor (responsiveness and latency) and locomotor (speed, acceleration, turning rate, turning angle and distance travelled in a fixed time, D(esc)) variables. We assessed whether variation in performance was temporally stable and we searched for any trade-offs among the components of the response that might explain why the variation persisted in the population. The coefficient of variation was high for all components, from 23% for turning rate to 41% for D(esc), highlighting the non-stereotypic nature of the response. Individual performance for all variables was significantly repeatable over five sequential responses at 30 min intervals, and also repeatable after a 30 day interval for most of the components. This indicates that the variation is intrinsic to the individuals, but there was no evidence for trade-offs amongst the components of the response, suggesting that, if trade-offs exist, they must be against other ecologically important behavioural or performance traits.
个体间生理表现特征的差异是稳定的，可以具有潜在的生态和进化意义。鱼类逃避反应在这方面很有趣，因为它是一种表现特征，个体间的差异可能决定个体的生存。然而，这种差异的时间稳定性在很大程度上尚未得到探索。我们在一个欧洲鲈鱼（Dicentrarchus labrax）种群中量化了逃避反应的各种成分的个体间差异，同时考虑了非运动（反应性和潜伏期）和运动（速度、加速度、转弯率、转弯角度和在固定时间内行进的距离，D(esc)）变量。我们评估了性能变化是否具有时间稳定性，并寻找反应成分之间的任何权衡，以解释为什么这种变化在种群中持续存在。所有成分的变异系数都很高，从转弯率的 23%到 D(esc)的 41%，突出了反应的非定型性质。所有变量的个体表现都在 30 分钟间隔的五次连续反应中显著可重复，并且在大多数成分中，在 30 天后也具有可重复性。这表明这种变化是个体内在的，但没有证据表明反应成分之间存在权衡，这表明，如果存在权衡，它们必须与其他生态上重要的行为或表现特征相对立。
