Pace-of-life syndromes (POLS) describe covariations between life history (such as growth rate and age at maturity), behaviour (e.g. activity or boldness) and physiology (e.g. metabolic rate) along an axis from fast to slow lifestyles. This powerful concept can be applicable at a range of scales, from broad interspecific contrasts to the individual intra-population level, though its generality has recently been questioned. Using two species of African annual fishes with fast lifestyles, we tested how individual-level POLS covary between the sexes and contrasting social environments. Measuring three key metabolic parameters (standard metabolic rate, SMR; maximum metabolic rate, MMR; and aerobic scope, AS), we found extensive variation between species and sexes in the expression of POLS. Social environment affected individual metabolic traits, but not their covariation with behaviour and life history traits. In accordance with the POLS prediction, we observed a positive association between MMR, AS and boldness, and a negative association between MMR, AS and lifespan in Nothobranchius orthonotus males, although trait covariations were opposite in N. orthonotus females. In Nothobranchius pienaari , we confirmed the predicted negative correlation between SMR and lifespan which was not sex-specific. Contrary to POLS predictions, we observed a negative correlation between SMR and boldness in N. pienaari . Finally, there was no link between activity levels or size at maturity and metabolic traits in either species. Overall, we demonstrated limited support for POLS predictions, but found that specific pace-of-life trait associations were mediated by both interspecific and intersexual differences.

中文翻译：

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一年生鳉鱼个体水平的生活节奏综合征是由两性和种间差异介导的

生活节奏综合征 (POLS) 描述了生活史（例如生长速度和成熟年龄）、行为（例如活动或大胆）和生理机能（例如代谢率）之间沿从快到慢生活方式的轴的协变。这个强大的概念可以适用于一系列范围，从广泛的种间对比到个体内部人口水平，尽管它的普遍性最近受到质疑。我们使用两种生活节奏快的非洲一年生鱼类，测试了个体水平的 POLS 如何在性别和对比的社会环境之间发生共变。测量三个关键代谢参数（标准代谢率，SMR；最大代谢率，MMR；和有氧范围，AS），我们发现 POLS 表达在物种和性别之间存在广泛差异。社会环境影响个体代谢特征，但不是它们与行为和生活史特征的协变。根据 POLS 预测，我们观察到 MMR、AS 和胆量之间呈正相关，而在 Nothobranchius orthonotus 雄性中，MMR、AS 和寿命之间呈负相关，尽管性状协变在 N. orthonotus 雌性中相反。在 Nothobranchius pienaari 中，我们证实了 SMR 与寿命之间的预测负相关，这不是性别特异性的。与 POLS 预测相反，我们观察到 SMR 与 N. pienaari 的大胆之间存在负相关。最后，两个物种的成熟时的活动水平或大小与代谢特征之间没有联系。总的来说，我们展示了对 POLS 预测的有限支持，