title: Insight into the heat resistance of fish via blood: Effects of heat stress on metabolism, oxidative stress and antioxidant response of olive flounder Paralichthys olivaceus and turbot Scophthalmus maximus.
abstract: High temperature has direct confinement on fish survival and growth, especially under the background of global warming. Selection of fish line with heat resistance is an important means to address this problem. In the present study, we analyzed the difference in heat resistance between families of olive flounder Paralichthys olivaceus and turbot Scophthalmus maximus, two flatfish species occupying slightly different thermal niches. Then the chosen families were tested to determine their differential response to heat stress (ΔT = +8 °C and +12 °C) in blood, including anaerobic metabolism (lactate), oxidative stress (lipid peroxidation and protein carbonylation) and antioxidant enzymes. Results showed a difference in heat resistance between families of the two species. Among the chosen parameters, growth traits had a significant effect on contents of lactate and malondialdehyd (MDA), and activities of catalase (CAT) and glutathione S-transferase in flounder (P < 0.05), and on MDA content and CAT activity in turbot (P < 0.05). In comparison with heat-sensitive family of each species, levels of all studied parameters were lower and more stable in heat-resistant families after heat stress. What's more, heat resistance of fish significantly influenced contents of lactate and MDA and activity of CAT in flounder (P < 0.05), as well as contents of lactate, MDA and carbonyl and activity of superoxide dismutate (SOD) in turbot (P < 0.05). These results demonstrated that such physiological phenotypes as anaerobic metabolism, oxidative stress and antioxidant enzymes are good biomarkers of fish heat-resistance, being potentially valuable in fish breeding. However, these markers should be applied with more caution when there is a growth discrepancy between fish families.
authors.affiliation: Key Laboratory of Experimental Marine Biology, National & Local Joint Engineering Laboratory of Ecological Mariculture, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, PR China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, PR China.
authors.forename: Yunliang
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Key Laboratory of Experimental Marine Biology, National & Local Joint Engineering Laboratory of Ecological Mariculture, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, PR China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, PR China.
authors.forename: Zhihao
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Shenghang Aquatic Science and Technology Co. Ltd., Weihai 264200, PR China.
authors.forename: Zongcheng
authors.initials: Z
authors.lastname: Song
authors.affiliation: Key Laboratory of Experimental Marine Biology, National & Local Joint Engineering Laboratory of Ecological Mariculture, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, PR China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, PR China.
authors.forename: Peng
authors.initials: P
authors.lastname: Xiao
authors.affiliation: School of Marine Science and Environment Engineering, Dalian Ocean University, Dalian 116023, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key Laboratory of Experimental Marine Biology, National & Local Joint Engineering Laboratory of Ecological Mariculture, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, PR China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, PR China.
authors.forename: Peijun
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Experimental Marine Biology, National & Local Joint Engineering Laboratory of Ecological Mariculture, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, PR China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, PR China. Electronic address: youfeng@qdio.cas.cn.
authors.forename: Feng
authors.initials: F
authors.lastname: You
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001774:Blood Chemical Analysis / Q000662:veterinary; D001790:Blood Physiological Phenomena; D004734:Energy Metabolism; D004789:Enzyme Activation / Q000502:physiology; D005412:Flatfishes / Q000097:blood / Q000502:physiology*; D006358:Hot Temperature; D018384:Oxidative Stress; D010088:Oxidoreductases / Q000378:metabolism*; D011897:Random Allocation; D000071436:Thermotolerance / Q000502:physiology
chemical_list: D000975:Antioxidants; D010088:Oxidoreductases
keywords: Anaerobic metabolism; Heat stress; Heat-resistance; Oxidative stress; Paralichthys olivaceus; Scophthalmus maximus