title: The physiological performance and immune responses of juvenile Amur sturgeon (Acipenser schrenckii) to stocking density and hypoxia stress.
abstract: Stocking density and hypoxia are considered priority issues in aquaculture research. In this study, two experiments were carried out in order to investigate the effects of chronic stress (stocking density) and acute stress (hypoxia) on the immune physiology responses (hematology, serum cortisol, glucose, total protein and the mRNA expression of CYP 1A) of juvenile Amur sturgeon (Acipenser schrenckii). In the chronic stress study, three triplicate groups of Amur sturgeon (42.0 ± 2.3 g) were reared in nine square concrete ponds (4.4 × 4.4 × 0.45 m³) at three stocking densities (3.7, 6.9 and 9.0 kg/m³) for 50 days. In the acute stress study, three triplicate groups: normal group (7 mg/l), hypoxia group 1 (5 mg/l) and hypoxia group 2 (3 mg/l) were used in nine 100 L indoor tanks. Sampling was performed at the end of the stocking density experiment (50 days) and at 0, 0.5, 1.5, 3 and 6 h after hypoxia stress. The results showed that increased stocking density reduced the morphological indexes (hepatosomatic index, spleen-somatic index and kidney-somatic index), while total protein and hemoglobin increased significantly in the stressed group. In response to hypoxia, the levels of cortisol, glucose and hematological parameters elevated significantly after this stress. As for spleen-somatic index, there was a decline after hypoxia though H1 group returned to the normal level at 3 h and 6 h after hypoxia stress. Additionally, In order to better understand the immune response of Amur sturgeon to chronic and acute stressors, we cloned the complete coding sequence of Amur sturgeon CYP 1A for the first time and investigated its tissue-specific expression and stress-induced expression. CYP 1A mRNA in liver showed over expressions both in crowding condition and in hypoxia stress. The same trend was also found in spleen and kidney which may provide evidence that CYP 1A could serve as a good indicator of immune response in Amur sturgeon. In addition, the result suggested a typical immune response both in high stocking density and hypoxia stress. But the chronically stressed fish might have an adaptation capability to survive under a stable crowding condition without a change in some immune parameters (cortisol, glucose, WBCs and RBCs).
authors.affiliation: Fisheries College, Ocean University of China, 5 Yushan Road, Qingdao, Shandong 266003, PR China.
authors.forename: Meng
authors.initials: M
authors.lastname: Ni
authors.affiliation: Fisheries College, Ocean University of China, 5 Yushan Road, Qingdao, Shandong 266003, PR China. Electronic address: wenhaishen@ouc.edu.cn.
authors.forename: Haishen
authors.initials: H
authors.lastname: Wen
authors.affiliation: Fisheries College, Ocean University of China, 5 Yushan Road, Qingdao, Shandong 266003, PR China.
authors.forename: Jifang
authors.initials: J
authors.lastname: Li
authors.affiliation: Fisheries College, Ocean University of China, 5 Yushan Road, Qingdao, Shandong 266003, PR China.
authors.forename: Meili
authors.initials: M
authors.lastname: Chi
authors.affiliation: Fisheries College, Ocean University of China, 5 Yushan Road, Qingdao, Shandong 266003, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Bu
authors.affiliation: Fisheries College, Ocean University of China, 5 Yushan Road, Qingdao, Shandong 266003, PR China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Ren
authors.affiliation: Fisheries College, Ocean University of China, 5 Yushan Road, Qingdao, Shandong 266003, PR China.
authors.forename: Mo
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Fisheries College, Ocean University of China, 5 Yushan Road, Qingdao, Shandong 266003, PR China.
authors.forename: Zhifei
authors.initials: Z
authors.lastname: Song
authors.affiliation: Fisheries College, Ocean University of China, 5 Yushan Road, Qingdao, Shandong 266003, PR China.
authors.forename: Houmeng
authors.initials: H
authors.lastname: Ding
mesh_terms: D000595:Amino Acid Sequence; D000693:Anaerobiosis; D000818:Animals; D001483:Base Sequence; D019363:Cytochrome P-450 CYP1A1 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D005398:Fisheries; D005399:Fishes / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D005786:Gene Expression Regulation; D006854:Hydrocortisone / Q000097:blood; D007113:Immunity, Innate; D008969:Molecular Sequence Data; D010802:Phylogeny; D011156:Population Density; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D016415:Sequence Alignment / Q000662:veterinary; D013312:Stress, Physiological
chemical_list: D029941:Fish Proteins; D019363:Cytochrome P-450 CYP1A1; D006854:Hydrocortisone
keywords: Acipenser schrenckii; Hypoxia; Immune response; Physiological performance; Stocking density