Liu Sheng, Fu Shi-Jian
Laboratory of Evolutionary Physiology and Behavior, Chongqing Key Laboratory of Animal Biology, Chongqing Normal University, Chongqing 401331, China.
Laboratory of Evolutionary Physiology and Behavior, Chongqing Key Laboratory of Animal Biology, Chongqing Normal University, Chongqing 401331, China
J Exp Biol. 2017 Dec 15;220(Pt 24):4711-4719. doi: 10.1242/jeb.167783. Epub 2017 Oct 30.
Metabolism, behaviour and growth are highly flexible in fish species, and inter-individual variation in these traits is evolutionarily and ecologically significant. It has long been suggested that these traits co-vary, although their relationships are debated. In the present study, we investigated whether metabolism, behaviour, growth and the potential relationships among them vary with food availability in sterile triploid carp. In this experimental animal model, we investigated the standard metabolic rate (SMR), growth performance and personality traits (i.e. activity, exploration and boldness) of juvenile individuals before and after 25 days of rearing in which fish were fed either once or twice a day to satiation. Inter-individual differences in SMR in each group showed high repeatability across the experimental period, and twice-fed fish showed higher SMRs than once-fed fish after 25 days of rearing. Compared with the once-fed group, the twice-fed group showed higher feeding rates (FRs) and lower feeding efficiencies (FEs) but similar specific growth rates (SGRs). None of the personality traits was affected by food availability. Furthermore, both boldness and exploration were highly repeatable throughout the experiment in the group fed twice a day, whereas only exploration showed repeatability in the group fed once a day. In the once-fed group, SMR and the personality traits were positively correlated with FR and negatively correlated with FE and/or SGR; however, these relationships did not exist in the twice-fed group due to the surplus of food. These results suggest that food availability significantly affects physiological, behavioural and ecological processes in these fish by altering the trade-off between metabolism and growth.
鱼类的代谢、行为和生长具有高度的灵活性，这些性状的个体间差异在进化和生态方面具有重要意义。长期以来，人们一直认为这些性状是共同变化的，尽管它们之间的关系仍存在争议。在本研究中，我们调查了不育三倍体鲤鱼的代谢、行为、生长以及它们之间的潜在关系是否会随着食物可获得性的变化而变化。在这个实验动物模型中，我们研究了幼鱼个体在每天喂食一次或两次直至饱足的25天饲养前后的标准代谢率（SMR）、生长性能和个性特征（即活动、探索和胆量）。每组中SMR的个体差异在整个实验期间表现出高度的重复性，饲养25天后，每天喂食两次的鱼比每天喂食一次的鱼表现出更高的SMR。与每天喂食一次的组相比，每天喂食两次的组显示出更高的摄食率（FRs）和更低的摄食效率（FEs），但特定生长率（SGRs）相似。个性特征均未受到食物可获得性的影响。此外，在每天喂食两次的组中，胆量和探索在整个实验过程中都具有高度的重复性，而在每天喂食一次的组中只有探索具有重复性。在每天喂食一次的组中，SMR和个性特征与FR呈正相关，与FE和/或SGR呈负相关；然而，由于食物过剩，这些关系在每天喂食两次的组中并不存在。这些结果表明，食物可获得性通过改变代谢和生长之间的权衡，显著影响了这些鱼类的生理、行为和生态过程。
