LED光色及注射褪黑素对虹鳟抗氧化酶活性及相关激素含量的影响

为探究光色对虹鳟抗氧化酶活性及相关激素含量的影响,对体质量(42.0±1.5) g的虹鳟进行了28 h的持续光照及注射褪黑素处理。实验设置白、红、绿、蓝4种光色,注射和不注射褪黑素两种处理方法,共8个处理组,分别在实验开始后的4、8、12、16、20、24和28 h取样,检测血清SOD和头肾CAT的活性以及血清皮质醇和褪黑素的含量。结果显示:①SOD和CAT活性以及皮质醇含量均呈现先下降后升高再下降后趋于平稳的趋势,在实验16 h处于较高水平,实验24～28 h趋于稳定。②SOD和CAT平均活性以及皮质醇平均含量均为红光下显著高于其他光色下,除CAT平均活性绿光与白光下差异不显著外,SOD活性和皮质醇含量均为绿光下显著低于其他光色下。③注射褪黑素使SOD和CAT活性以及皮质醇含量在28 h持续光照过程中呈下降趋势;相比较未注射处理组,注射褪黑素在各光色下均可显著降低SOD和CAT活性及皮质醇含量,提高褪黑素含量。研究表明,在28 h急性光照射下,虹鳟在16 h受到的胁迫最强烈,实验后期机体逐渐适应光环境;红光对虹鳟氧化胁迫最强烈,绿光对虹鳟基本不产生胁迫;注射褪黑素可缓解光照对虹鳟的胁迫作用。     

光色对红壳色中华绒螯蟹生长、摄食及体色的影响

本研究旨在探讨光色对红壳色中华绒螯蟹(Eriocheir sinensis)仔蟹生长、摄食及体色的影响,为其体色研究提供参考。固定光照强度为(1 800.0±50.0)Lx,记录观察红壳色与正常壳色仔蟹在5种常见光色(红、绿、黄、白和蓝)下养殖35 d的存活、相残、蜕壳、生长及摄食量等情况,并利用色调-饱和度-亮度(HSB)颜色模型分析体色变化。Duncan多重比较分析发现:不同颜色光照对两种壳色中华绒螯仔蟹生长的影响不同。绿光有利于红壳色仔蟹的生长,而黄光则对正常壳色仔蟹更有利。两种壳色仔蟹的体质量特定生长率和致残率在不同颜色光照中差异显著。红壳色仔蟹在红光和绿光中的蜕壳率明显高于正常壳色仔蟹(P0.05)。除蓝光组外,各颜色光照中正常壳色仔蟹致残率均高于红壳色仔蟹,其中白光组的致残率比红壳色仔蟹高78.72%(P0.01)。红壳色仔蟹在绿光组中的体质量特定生长率(1.69%/d)和头胸甲特定生长率(0.69%/d)最高;在红光组中特定生长率最低(分别为1.40%/d,0.38%/d),而正常壳色仔蟹在蓝光中的特定生长率最低。两种壳色仔蟹各光色组的夜间摄食占比均高于白昼,尽管差异不显著(P0.05),但表现出了昼夜摄食节律。红壳色仔蟹的日摄食率、食物转化率受光照颜色影响不明显(P0.05)。但对正常壳色仔蟹蓝光会抑制摄食和食物转化,而黄光则会促进摄食和食物转化。与蜕壳前相比,蜕壳后红壳色仔蟹红光、绿光、黄光组H值下降,红色加深;而白光、蓝光组H值上升,红色变浅;各组S值、B值下降,体色变浅,变暗,而正常壳色仔蟹红色深浅度在不同光照下则表现相反;除红光、黄光B值上升,体色变亮,S值均下降,体色变浅。因此,绿光和黄光分别利于红壳色和正常壳色仔蟹的生长,而绿光能促进两种壳色仔蟹体色变黑,加深。本研究将为中华绒螯蟹体色形成与调控机理的解析,以及养殖过程中光照条件的优化提供参考。     

秦岭细鳞鲑稚鱼对底质颜色、光照强度及光色的选择行为

光照、底质颜色是影响鱼类行为、生存的重要环境因子,为探究秦岭细鳞鲑(Brachymystax tsinlingensis)稚鱼对光照及底质颜色环境偏好,本研究以秦岭细鳞鲑子代为实验鱼[平均全长为(3.31±0.67) cm;平均体重为(0.42±0.18) g]开展了秦岭细鳞鲑稚鱼对底质颜色、光照强度及光照颜色的选择行为。结果显示,秦岭细鳞鲑稚鱼个体与群体均对黑色底质偏好明显;个体对3种光照强度(弱光区为1~5 lx,过渡区为5~10 lx,强光区为10~25 lx)均无明显趋向性(P>0.05),而群体对强光(10~25 lx)有明显趋避性;在相同光照强度(1~3 lx)下,个体对4种光照颜色(黄、红、绿和蓝)无明显趋向性(P>0.05),而群体对绿光有明显趋避性(P<0.05)。秦岭细鳞鲑个体和群体对光照强度和光照颜色的差异性表现可能与其信息传递特征或环境反应机制不同有关,而个体和群体均偏好黑色底质,其偏好光照强度为1~10 lx,对绿光具有趋避性,这可能与该物种生活环境特征相关。本研究结论可进一步为秦岭细鳞鲑苗种培育和增殖放流环境选择提供参考。     

传染性造血器官坏死病毒表面糖蛋白基因核酸疫苗的构建及对虹鳟血液生化指标的影响

为研究传染性造血器官坏死病毒(infectious hematopoietic necrosis virus, IHNV)表面糖蛋白(glycoprotein, G)基因核酸疫苗对虹鳟免疫保护效果及血液生化指标的影响,将IHNV G基因克隆至pMD19-T载体中,连接产物在DH5α中进行转化,获取重组质粒pMD19-TG后回收G基因片段。将鉴定正确的G基因片段利用Bam H I和Xho I酶切位点克隆在真核表达载体pVAX1上,构建核酸疫苗pVAX1-G。重组质粒pVAX1-G按照8μg/尾的剂量注射虹鳟设为pVAX1-G组,同时设8μg/尾空质粒组、PBS对照组和空白组,于免疫后21 d,以100倍半数组织培养感染剂量(tissue culture infective dose, TCID50)通过腹腔注射的方式进行攻毒实验,计算核酸疫苗相对保护率(relative percent survival, RPS),攻毒后收集免疫虹鳟血清进行血液指标检测。结果显示,攻毒后虹鳟血清中16项指标中谷丙转氨酶(ALT)、谷草转氨酶(AST)、碱性磷酸酶(ALP)、总胆红素(TBIL)、总胆汁酸(TBA)、葡萄糖(GLU)、尿素(Urea)、肌酐(CREA)、总蛋白(TP)、白蛋白(ALB)和球蛋白(GLO)与正常虹鳟相比有显著变化,空载组11项指标较pVAX1-G组变化显著;攻毒后14 d pVAX1-G组累积死亡率为19%(19/100),而空载组和PBS对照组分别为62%(62/100)和85%(85/100)。pVAX1-G核酸疫苗对虹鳟免疫保护率为78%。病理学观察发现,免疫pVAX1-G组虹鳟的肝脏、脾脏、肾脏组织未见明显损伤。综上表明,pVAX1-G作为核酸疫苗有助于减轻IHNV对虹鳟的损伤,对IHNV有较好的免疫保护效果。     

池塘循环水槽养殖模式下吉富罗非鱼的生长及生理响应变化

为探讨在池塘循环水槽养殖模式下吉富罗非鱼不同养殖密度的生长特性和生理指标变化,评估吉富罗非鱼在池塘循环水槽养殖模式下的适宜养殖密度,以吉富罗非鱼为实验对象,设计传统池塘养殖模式放养密度5尾/m~2 (SD1组),池塘循环水槽养殖模式放养密度180尾/m~2 (SD2组)和270尾/m~2 (SD3组),比较各组吉富罗非鱼的生长性能,分析血液生化指标和肝脏HSP70 mRNA表达量的变化规律。结果显示,经过120 d的养殖,SD2组吉富罗非鱼终末体质量、特定生长率和绝对生长率显著高于SD1和SD3组。SD2和SD3组存活率、体质量差异系数和饵料系数低于SD1组。SD2组血清皮质醇、血清谷丙转氨酶、谷草转氨酶、溶菌酶水平和肝脏HSP70 mRNA的相对表达量在30 d时显著高于SD1组。SD3组血清皮质醇和葡萄糖水平在60 d后持续上升,120 d时显著高于SD1组,谷丙转氨酶、谷草转氨酶、溶菌酶水平和肝脏HSP70 mRNA的相对表达量在60、90 d时显著高于SD1组,甘油三酯在整个实验期显著低于SD1组。SD2组吉富罗非鱼在养殖前期受到环境胁迫,中后期适应环境;SD3组在养殖中后期受到环境胁迫,长期处于应激状态。吉富罗非鱼生长和血清生理指标,池塘循环水槽养殖吉富罗非鱼的适宜养殖密度为180尾/m~2,在该密度下罗非鱼能适应养殖环境,养殖效果优于传统养殖模式。     

光色和光照周期对大西洋鲑银化期生长及生理的影响

为探讨大西洋鲑(Salmo salar)银化期间光色和光照周期对其生长及生理的影响,采用单因素分析法,设计3种光照周期和3种光源颜色,在红光条件下,设置24 h开灯(24L∶0D)(全光照)、24 h关灯(0L∶24D)(无光照)以及12 h开灯12 h关灯(12L∶12D)(半光照)3种光照周期,在半光照条件下,设置红光、白光和蓝光3种LED光源颜色。试验周期为4个月,测定各组大西洋鲑的生长性能指标及血清生化指标。结果显示,半光照时,大西洋鲑的日增重和特定生长率显著高于无光照组(P0.05),而饲料系数显著低于其他两组(P0.05)。光源颜色对大西洋鲑银化期的生长具有显著影响(P0.05),采用红光时,大西洋鲑的日增重最高,白光组次之,蓝光组最低,而饲料系数呈现相反的规律。盐度耐受试验表明,半光照组的死亡率为10%,显著低于其他两组(P0.05),而红光组死亡率约为10%,显著低于白光组和蓝光组(P0.05)。血清指标分析表明,半光照组的钠离子和氯离子含量低于其他两组,说明该组的大西洋鲑在海水中具备了渗透压调节的能力。综上,红光光源半光照为大西洋鲑银化期的适宜养殖条件。     

光谱对红鳍东方鲀幼鱼肠道微生物组成的影响

为探究光谱对红鳍东方鲀幼鱼肠道微生物组成的影响，以红鳍东方鲀幼鱼为研究对象，在5种不同光谱(蓝光、绿光、红光、白光、黄光)条件下对其受精卵进行孵化和饲育共90 d。试验结束后对各组幼鱼体长进行测定，采用Illumina HiSeq高通量测序技术对其肠道微生物的组成进行分析。结果显示，绿光组、黄光组和白光组的幼鱼体长显著高于蓝光组和红光组(P<0.05),且幼鱼存活率蓝光组>红光组>黄光组>白光组>绿光组。以相似度为97%的聚类分析显示，蓝光组、绿光组、红光组、白光组和黄光组的红鳍东方鲀肠道微生物的运算分类单元数分别为631、508、530、513、418个，共有运算分类单元数87个，特有运算分类单元数为0,但蓝光组和红光组共有的运算分类单元数为13。蓝光组Ace和Chao指数显著高于黄光组(P<0.05),即蓝光组的微生物菌群的丰富度最大，黄光组最小。蓝光组和红光组Shannon指数显著高于绿光组和黄光组(P<0.05),即蓝光组和红光组的肠道微生物菌群多样性大于绿光组和黄光组。属水平肠道菌群分布显示，弓形杆菌属、弧菌属、支原体等为红鳍东方鲀幼...     

LED光谱对红鳍东方鲀仔稚鱼形态性状及生长相关基因表达的影响

设置4种LED光谱环境,分别为蓝(λ450 nm)、绿(λ525 nm)、黄(λ590 nm)和白(λ400~780n m),水温控制在(22±1)℃,光周期为16L:8D,光强设为200 mW/m2。研究光谱对红鳍东方鲀(Takifugu rubripes)受精卵孵化和孵化后1~18 d (即实验第6~23天)仔稚鱼形态性状(全长、体长、躯干长、尾长、头长、眼径和体高)以及生长相关基因,包括生长激素(GH)、生长激素受体1型(GHR1)、类胰岛素生长因子1型(IGF1)基因相对表达量的影响。结果显示,蓝、绿、黄光处理组的受精卵比白光处理组早2 d孵化;在实验结束时,蓝光处理组中,仔稚鱼的全长、体长、躯干长和尾长生长最快,黄光处理组中,头长、眼径和体高生长最快。对于生长相关基因,蓝光下的GH基因表达量显著高于黄、白光组(P<0.05),但与绿光组无显著性差异;不同光谱下,GHR1、IGF1基因的表达量无显著性差异。结果表明,蓝光、绿光和黄光促进红鳍东方鲀受精卵的孵化,蓝光有利于红鳍东方鲀仔稚鱼的生长发育。本文研究了不同光谱对红鳍东方鲀仔稚鱼早期发育的形态性状及生长相关基因表达的影响,为养殖厂对红鳍东方鲀育苗提供科学的参考依据。     

光照对短须裂腹鱼生长及生理影响研究

光照是影响鱼类活动、摄食和生长的主要环境因子之一。本文分别以野生和养殖短须裂腹鱼(Schizothorax wangchiachi)为研究对象,研究了短须裂腹鱼对光谱、光强选择趋向性及光谱对短须裂腹鱼生长、生理的影响。结果显示,黄光、红光和绿光都对短须裂腹鱼起到吸引作用;利用黄光进行光照强度选择性研究发现,在低光照强度范围(22.6~64.7 lx),短须裂腹鱼对光强的趋向性没有显著差异(P>0.05);为期56 d的养殖实验发现,不同的光照颜色显著影响短须裂腹鱼的生长率和存活率(P<0.05),黄光和自然光处理组的养殖效果无显著性差异;无论在生长率和应激水平,均优于蓝光环境,蓝光提升了短须裂腹鱼的应激水平,导致存活率下降。研究结果可为水利工程建设过鱼设施诱鱼光源的选择提供科学依据。     

中草药添加剂对鲁氏耶尔森菌感染虹鳟血液生化指标的影响

为研究复方中草药对鲁氏耶尔森菌(Yersinia ruckeri)感染虹鳟(Oncorhynchus mykiss)后其血液生化指标的影响,在虹鳟饲料中分别添加两种复方中草药(复方1组、复方2组),持续投喂28 d。在第28天感染鲁氏耶尔森菌,检测感染后72 h的血清生化指标,并统计各组存活率。结果显示:复方中草药组对虹鳟增重无抑制作用。添加复方中草药可提高虹鳟感染鲁氏耶尔森菌后的存活率,其中复方2组的保护效果最好。感染72 h后,复方2组总蛋白、白蛋白、球蛋白、甘油三酯、总胆固醇含量和碱性磷酸酶活性均高于对照组。复方2组谷丙转氨酶、谷草转氨酶活性低于对照组,乳酸脱氢酶活性显著低于对照组。复方1组和复方2组尿酸含量显著低于对照组。复方中草药组总胆红素、尿素氮、肌酐和血糖含量与对照组相比无显著性差异。结果表明,添加复方中草药能提高鲁氏耶尔森菌感染后虹鳟的存活率,其中复方2组的保护效果最好。     

柱形病对黄颡鱼血液生化指标的影响

为探究柱形病对黄颡鱼(Pelteobagrus fulvidraco)生理机能的影响,随机选取患病和健康黄颡鱼各10尾,采集其血液,静置后离心分离血清以测定血液生化指标如皮质醇、乳酸(LD)含量,乳酸脱氢酶(LDH)、碱性磷酸酶(ALP)活性,葡萄糖、白蛋白(ALB)、总蛋白(TP)、尿素氮(BUN)、总胆固醇(TCHO)、高密度脂蛋白胆固醇(HDLC)、低密度脂蛋白胆固醇(LDLC)含量,谷草转氨酶(AST)、谷丙转氨酶(ALT)活性。结果显示:患病黄颡鱼血清皮质醇浓度和LDH、AST活性均极显著高于健康鱼,LD含量和ALT活性显著高于健康鱼。与健康鱼相比,患病黄颡鱼血清葡萄糖含量极显著降低,而HDLC、LDLC、TCHO、ALB、TP、BUN浓度和ALP活性无显著差异。健康鱼肝细胞呈近圆形,形状较规则,细胞界线清晰,细胞核多位于细胞中央,呈圆形或椭圆形,肝细胞以中央静脉为中心形成放射状排列。患病鱼肝细胞出现局部坏死、空泡化,形成坏死灶,伴有大量中性粒细胞、淋巴细胞浸润。结果表明:柱状黄杆菌感染可引起黄颡鱼鱼体显著的应激反应,并引起鱼体肝脏损伤。     

患肌肉溃烂病中华倒刺鲃血清生化指标变化

采集嘉陵江网箱养殖中华倒刺鲃(Spinibarbus sinensis Bleeker)病鱼和健康鱼,测定二者血清谷草转氨酶(AST)、谷丙转氨酶(ALT)、碱性磷酸酶(AKP)、胆固醇(CHOL)、甘油三酯(TG)、血糖(GLU)、肌酐(CREA)、尿素(UREA)、总蛋白(TP)、白蛋白(ALB)、血清氯(Cl-)、血清钙(Ca2+)等指标并进行对比。结果显示,相对于健康鱼,病鱼ALT、AST、Cl-和Ca2+显著升高(P<0.05);AKP、TP、ALB显著降低(P<0.05);TG、GLU、CREA和UREA虽未体现显著差异(P>0.05),但两组间有较大差别。整体而言,肌肉溃烂病引起中华倒刺鲃肌肉、肝、肾等多种重要组织器官病变,相应血清指标出现明显变化。     

Effects of long-term silymarin oral supplementation on the blood biochemical profile of rainbow trout (<Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis>)

Silymarin, an extract from “milk thistle” (Silybum marianum) plant is traditionally used as herbal medicine. The present study was conducted to investigate the clinical effects and possible side effects of silymarin on biochemical blood parameters of rainbow trout (Oncorhynchus mykiss). Fishes were treated with 0 (control), 100, 400, and 800 mg of silymarin per kg of food during 4 weeks. Plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), creatine kinase (CK), glucose, total protein, creatinine, triglyceride, cholesterol, urea, uric acid and liver cellular total antioxidant, and protein content were measured after 7, 14, and 28 days of silymarin treatment. The results showed that oral administration of silymarin in fish significantly reduced plasma glucose and cholesterol levels and relatively increased plasma total protein and globulin concentrations (P < 0.05). Increasing plasma albumin levels indicate the important role of albumin in drug transportation in circulatory system of fish. Silymarin also stabilized cellular membrane structure and regulated the levels of AST, ALT, ALP, CK, and LDH activity. In conclusion, on the basis of these results, oral administration of silymarin up to 400 mg per 1 kg of food has no side effect on blood biochemical and clinical parameters of fishes. However, oral administration of 800 mg/kg- of silymarin caused cytotoxicity and modifications in blood biochemical parameters of fish.     

Anaesthetic efficacy and biochemical effects of 1,8‐cineole in rainbow trout (Oncorhynchus mykiss,Walbaum, 1792)

The aim of the present study was to investigate the anaesthetic efficacy and biochemical effects of 1,8‐cineole (cineole) in rainbow trout (Oncorhynchus mykiss). The fish were exposed to 200, 300, 400, 500, 600 and 800 μl/L cineole and time of induction of anaesthesia and recovery from anaesthesia were recorded. Thereafter, the fish haematological and biochemical responses to anaesthesia with different concentrations of cineole were studies. Moreover, the haematological and biochemical response of fish anaesthetized for 300 s with either cineole (283 μl/L) or eugenol (25 μl/L) were compared. Cineole at the concentrations of 200–800 μl/L induced stages 2, 3 and 4 anaesthesia within 109‐29.3, 226‐59 and 418‐117 s respectively. Increase in anaesthesia induction time led to higher stress responses and enzymes’ activity characterized by elevation in red blood cell (RBC), white blood cell (WBC), blood haematocrit and haemoglobin, and plasma cortisol, glucose and lactate levels, and aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase and creatine phosphokinase (CPK) activities. However, cineole concentrations had no significant effects on plasma alanine aminotransferase (ALT) activity and ions levels. Comparison of cineole with eugenol showed that cineole showed less change in blood RBC and plasma AST, ALP, CPK, cortisol and glucose levels compared to eugenol. In conclusion, cineole is efficient to anaesthetize trout at concentrations of 200–800 μl/L. Increase in cineole concentration shortens anaesthesia induction time, stress response and probably tissue damage. The concentrations of 600–800 μl/L cineol is recommended for rapid sampling as it causes the least stress and enzymatic responses. The present results suggest that cineole causes slightly lower side effects in trout compared to eugenol.     

光照对中华鲟幼鱼生长及血液生化指标的影响

测定了自然光周期(对照组,白天平均76 lx、晚上0 lx)、全光照(940 lx)和全避光(0 lx)三种光照周期下养殖70 d的中华鲟幼鱼生长指标(体重、全长、体长)及血液生化指标。结果显示,3种光照周期下的中华鲟幼鱼的生长无显著性差异。全避光组中华鲟幼鱼血液中总蛋白(TP)、白蛋白(ALB)、球蛋白(GLB)含量最低,与对照组有显著性差异,与全光照组无显著性差异;甘油三酯(TRIG)、肌酐(CREA)和谷草转氨酶(AST)含量最高,TRIG与对照组有显著性差异,与全光照组无显著性差异,CREA与全光照组和对照组均有显著性差异,AST均无显著性差异。全光照组中华鲟血液中血清总胆固醇(TC)、总胆红素(T-BIL)、谷丙转氨酶(ALT)、谷草转氨酶(AST)含量最低,但与全避光组和对照组均无显著性差异;葡萄糖(GLU)、尿素氮(BUN)含量最高,与全避光组和对照组均有显著性差异。对照组的乳酸脱氢酶(LDH)和碱性磷酸酶(ALP)含量最高,LDH与全光照组和全避光组均无显著性差异,ALP与全光照组和全黑暗组均有显著性差异。三种光照周期下的无机离子含量除Mg2+外,Na+、K+、Cl-、Ca2+、P3+都没有显著性差异。     

Elevation of plasma cortisol and hypertrophic response of inter-renal and chromaffin tissues of rainbow trout, Oncorhynchus mykiss (Walbaum), to the harmful diatom Chaetoceros concavicornis

Abstract. Changes in plasma cortisol concentrations and inter-renal and chromaffin tissues of rainbow trout, Oncorhynchus mykiss (Walbaum), exposed to harmful concentrations of the diatom Chaetoceros concavicornis were investigated. The plasma cortisol level of trout exposed to C. concavicornis was over 10-fold greater than that of untreated trout. Computer-assisted feulgen-microspectrophotometry was employed in order to assess the activity of inter-renal and chromaffin cells. The total areas of inter-renal and chromaffin nuclei in trout treated with C. concavicornis significantly increased compared to those of untreated fish. In contrast, the chromatin density of inter-renal and chromaffin nuclei in treated trout decreased significantly. This decrease of chromatin density in treated fish was caused by an increase in the low-density components, and a decrease in the middle-density and high-density components. Although the hypertrophic changes to the inter-renal and chromaffin nuclei of treated fish exhibited the same general trend, the extents to which the changes took place were different, occurring more rapidly within inter-renal tissues. The rainbow trout exposed to harmful concentrations of C. concavicornis were experiencing a severe physiological disturbance to which they tried to adapt.     

水霉病对草鱼血液生化指标和肌肉泛素-蛋白酶体系统的影响

本研究探讨了感染水霉病后草鱼(Ctenopharyngodon idellus)的血液生化特性和肌肉泛素-蛋白酶体系统(UPS)活性变化。随机选取患病和健康草鱼各10尾,测定血清葡萄糖(GLU)、白蛋白(ALB)、总蛋白(TP)、胆固醇(CHO)及甘油三酯(TG)含量和乳酸脱氢酶(LDH)、碱性磷酸酶(ALP)、谷草转氨酶(AST)及谷丙转氨酶(ALT)活性,检测肌肉nrf2、hsp70、hsp90和UPS相关基因表达,并定量测定了肌肉组织泛素化蛋白水平。结果显示,感染水霉病草鱼的血清CHO、ALB、TP和TG浓度显著下降,AST和LDH活性显著提高,患病草鱼肌肉组织nrf2、hsp70和hsp90的mRNA表达量显著升高。水霉病显著上调了肌肉chip、ub、psma2、psmc1、murf1和mafbx的mRNA表达水平和泛素化蛋白含量。感染水霉病改变了草鱼血清生化指标,诱导草鱼机体产生细胞应激反应,显著上调了骨骼肌泛素-蛋白酶体系统的活性。研究结果可为水霉病的诊断和防治提供科学的参考依据。     

Effects of Rosemary (Rosmarinus officinalis) extract on growth,blood biochemistry,immunity, antioxidant,digestive enzymes and liver histopathology of rainbow trout,Oncorhynchus mykiss

This research was designed to determine the effects of rosemary (Rosmarinus officinalis) extract on growth, blood biochemistry, immunity, antioxidant, digestive enzymes and liver histopathology of rainbow trout. In a 40‐day diet experiment, rainbow trout was fed with the experimental diets containing 0.4, 0.7, 1 and 3 g/kg of rosemary. 0.4 and 0.7 g/kg rosemary extracts had no significant effect on all parameters studied (p > .05). The growth performance (SGR and WG) and feed utilization (FCR and FER) of the fish increased with the increase in the rate of rosemary in the feed (p < .001). Additionally, only the final weight levels were significant at the linear level (p < .05). Rosemary's 1 and 3 g/kg doses increased total protein, trypsin, amylase, lipase, superoxide dismutase (SOD), catalase (CAT), lysozyme, total immunoglobulin (IG) and white blood cell (WBC) levels when compared to control group. However, glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol and triglyceride levels decreased significantly (p < .001). Moreover, these doses of rosemary caused a significant reduction in steatosis of liver hepatocytes compared to the control group. In conclusion, the present study showed that rosemary may be useful in reducing the stress effects by increasing the growth, antioxidant, digestive enzymes and immunity levels, as well as reducing the rate of steatosis in the liver of rainbow trout.     

Quantifying risks of volitional consumption of New Zealand Mudsnails by Steelhead and Rainbow Trout

To assess the risk of transferring alien, invasive New Zealand mudsnails (NZMS) Potamopyrgus antipodarum with shipments of live rainbow or steelhead trout Oncorhynchus mykiss, we conducted laboratory trials to quantify and determine the volitional ingestion of snails from the bottom of laboratory tanks. Approximately, 2000 snails were placed on the bottom of a test tank and groups of 10 fish were added to each tank. After 48 h, the fish were removed, euthanized and the snails in the gastrointestinal tract were counted, and the proportion of snails remaining in each tank was measured. We found that both rainbow trout and steelhead consumed NZMS, but rainbow trout consumed nearly twice the number of snails that were consumed by steelhead trout. Feeding fish a maintenance diet increased the total consumption of snails by fish to an average of 64.5 snails per rainbow trout. Our study suggests that management strategies that depurate fish without feed for 48 h to reduce the risk of transfer of NZMS are not viable in preventing the transport of snails if rearing waters contain snails.     

Effects of dietary cholesterol supplementation on growth and cholesterol metabolism of rainbow trout (Oncorhynchus mykiss) fed diets with cottonseed meal or rapeseed meal

This study was conducted to evaluate the effects of cholesterol on growth and cholesterol metabolism of rainbow trout (Oncorhynchus mykiss) fed diets with cottonseed meal (CSM) or rapeseed meal (RSM). Four experimental diets were formulated to contain 550 g kg^?1 CSM or 450 g kg^?1 RSM with or without 9 g kg^?1 supplemental cholesterol. Growth rate and feed utilization efficiency of fish fed diets with 450 g kg^?1 RSM were inferior to fish fed diets with 550 g kg^?1 CSM regardless of cholesterol level. Dietary cholesterol supplementation increased the growth rate of fish fed diets with RSM, and growth rate and feed utilization efficiency of fish fed diets with CSM. Similarly, dietary cholesterol supplementation increased the plasma total cholesterol (TC), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triiodothyronine levels, but decreased the plasma triglycerides and cortisol levels of fish fed diets with RSM or CSM. In addition, supplemental cholesterol increased the free cholesterol and TC levels in intestinal contents, but decreased the hepatic 3-hydroxy-3-methyl-glutaryl-CoA reductase activity of fish fed diets with RSM or CSM. These results indicate that 9 g kg^?1 cholesterol supplementation seems to improve the growth of rainbow trout fed diets with CSM or RSM, and the growth-promoting action may be related to the alleviation of the negative effects caused by antinutritional factors and/or make up for the deficiency of endogenous cholesterol in rainbow trout.