Effects of Stocking Density on the Growth Performance, Physiological Parameters, Redox Status and Lipid Metabolism of Micropterus salmoides in Integrated Rice–Fish Farming Systems

Abstract

Stocking density has been identified as one of the main factors affecting fish growth, welfare and behavior. However, few studies have focused on the effects of stocking density on fish health in integrated rice–fish farming systems. Thus, the aim of this study was to evaluate the effects of different stocking densities on the growth performance, physiological parameters, redox status and lipid metabolism of Micropterus salmoides in an integrated rice–fish farming system. The fish were reared at three densities: low density (LD, 40 g/m3), medium density (MD, 80 g/m3) and high density (HD, 120 g/m3) for 90 days. At the end of the experiment, fish reared in the MD and HD groups showed lower growth performance than those from the LD group. The HD treatment significantly altered the physiological parameters, including glucose and lactate. Meanwhile, the HD treatment induced oxidative stress and lipid peroxidation after 90 days of farming. Furthermore, transcriptomic analysis revealed that HD treatment led to abnormal lipid metabolism. Interestingly, we found the suppression of three key pathways related to lipid metabolism, including the PPAR, insulin and adipocytokine signaling pathways, in the HD group. Overall, our data indicated that the HD treatment inhibited growth and caused physiological responses, oxidative stress and abnormal hepatic lipid metabolism in M. salmoides in an integrated rice–fish farming system.

Effects of stocking density on the growth performance, mitophagy, endocytosis and metabolism of Cherax quadricarinatus in integrated rice–crayfish farming systems

“…Hence, it is generally recognized that the content of MDA can reflect the level of oxidative damage in organisms ( Han et al, 2022 ). It has been reported that the content of MDA significantly increased with the increasing stocking density in many aquatic animals, such as M. salmoides ( Jia et al, 2022 ), S. maximu ( Jia et al, 2016 ), and blunt snout bream ( Megalobrama amblycephala ) ( Wang et al, 2018 ). In this study, the significant increase of MDA content in the HD group also proved that long-term high stocking density caused oxidative stress.…”

“…Under a high stocking density, glucose metabolic enzymes were activated, which enhanced energy production to resist the environment stimuli in abalone ( Haliotis discus hannai ) ( Gao et al, 2018 ). A transcriptomic analysis of M. salmoides indicated that high stocking density caused abnormal lipid metabolism ( Jia et al, 2022 ). In line with previous studies, our data also showed that the metabolic function of hepatopancreas, such as organonitrogen compound catabolic process, proteolysis involved in cellular protein catabolic process, modification-dependent protein catabolic process and cellular protein catabolic process, was significantly influenced by high stocking density.…”

Concise synthesis of deuterium-labelled proanthocyanidin metabolite 5-(3′,4′-dihydroxyphenyl)-γ-valerolactone as an analytical tool

“…19 Understanding the bioavailability of DHPV aer PACs oral intake is of paramount importance for harnessing their health benets and designing functional food products. [20][21][22][23][24] In this regard, quantitative bioanalytical methods based on stable isotopically labelled (SIL) analogs represent a valuable tool to pursue these goals. In particular, the use of isotopic labelled internal standard in mass spectrometry allows to have the best results in terms of precision and accuracy when quantifying the unknown amount of molecule of interest in a biological matrix.…”

Scale Cortisol Modulation in Cultured Nile Tilapia (Oreochromis niloticus): Deciphering the Intricate Role in Chronic Stress through Mitogen-Activated Protein Kinase Signaling Pathway Regulation

“…Stocking density is an important factor determining the profitability of an aquaculture venture and farmers tend to increase stocking with the aim of increasing productivity (Oke and Goosen 2019). High stocking density has been shown to produce a chronic stress situation in Gilthead sea bream (Jia et al 2022), the same husbandry practice has also been shown to induce chronic stress which elevates the levels of plasma cortisol and glucose in O. niloticus (Aketch et al 2014).…”