Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI), Am Handelshafen 12, 27570, Bremerhaven, Germany.
Faculty of Agricultural and Environmental Sciences, University of Rostock, Aquaculture and Sea-Ranching, Justus-Von-Liebig-Weg 6, 18059, Rostock, Germany.
Metabolomics. 2024 Feb 12;20(2):23. doi: 10.1007/s11306-023-02077-9.
Animal welfare in aquaculture is becoming increasingly important, and detailed knowledge of the species concerned is essential for further optimization on farms. Every organism is controlled by an internal clock, the circadian rhythm, which is crucial for metabolic processes and is partially influenced by abiotic factors, making it important for aquaculture practices.
In order to determine the circadian rhythm of adult turbot (Scophthalmus maximus), blood samples were collected over a 24-h period and plasma metabolite profiles were analyzed by H-NMR spectroscopy.
The fish were habituated to feeding times at 9 am and 3 pm and with the NMR spectroscopy 46 metabolites could be identified, eight of which appeared to shift throughout the day.
We noted exceptionally high values around 3 pm for the amino acids isoleucine, leucine, valine, phenylalanine, lysine, and the stress indicator lactate. These metabolic peaks were interpreted as either habituation to the usual feeding time or as natural peak levels in turbot in a 24-h circle because other indicators for stress (glucose, cortisol and lysozymes) showed a stable baseline, indicating that the animals had no or very little stress during the experimental period.
This study provides initial insights into the diurnal variation of metabolites in adult turbot; however, further studies are needed to confirm present findings of possible fluctuations in amino acids and sugars. Implementing optimized feeding times (with high levels of sugars and low levels of stress metabolites) could lead to less stress, fewer disease outbreaks and overall improved fish welfare in aquaculture facilities.
水产养殖中的动物福利正变得越来越重要，详细了解相关物种对于养殖场的进一步优化至关重要。每个生物体都受内部生物钟——昼夜节律的控制，它对代谢过程至关重要，并部分受非生物因素的影响，这使其对水产养殖实践很重要。
为了确定成体大菱鲆（Scophthalmus maximus）的昼夜节律，在 24 小时内采集血液样本，并通过 H-NMR 光谱分析血浆代谢物谱。
将鱼适应于早上 9 点和下午 3 点的进食时间，并通过 NMR 光谱鉴定出 46 种代谢物，其中有 8 种似乎全天都在变化。
我们注意到下午 3 点左右的氨基酸异亮氨酸、亮氨酸、缬氨酸、苯丙氨酸、赖氨酸和应激标志物乳酸的值异常高。这些代谢峰值被解释为对通常进食时间的适应，或者是大菱鲆在 24 小时周期中的自然峰值水平，因为其他应激指标（葡萄糖、皮质醇和溶菌酶）显示出稳定的基线，表明在实验期间动物没有或只有很少的应激。
本研究初步了解了成体大菱鲆代谢物的昼夜变化；然而，需要进一步的研究来证实氨基酸和糖可能波动的现有发现。实施优化的喂食时间（高糖水平和低应激代谢物水平）可以减少应激、减少疾病爆发，并整体改善水产养殖设施中的鱼类福利。
