七种养殖特色淡水鱼脏器系数的测定和比较

为研究养殖特色淡水鱼成鱼主要脏器系数,并探讨各品种组织器官重量与体重的关系,本研究对杂交鲟(俄罗斯鲟Acipenser gueldenstaedti♀×史氏鲟A.schrenckii♂)、斑点叉尾(鮰)(Ietalurus punetaus)、鳜(Siniperca chuatsi)、大口黑鲈(Micropterus ...     

以色列红罗非鱼与其他罗非鱼群体杂交子一代在海水中生长性能分析

利用以色列红罗非鱼品系(Israel strain of red tilapia,R)、吉富品系(GIFT strain of Nile tilapia,J)(Oreochromis niloticus)、奥利亚罗非鱼(Blue tilapia,A)(O.aureus)、尼罗罗非鱼(Nile tilapia,N)(O.niloticus)等群体,构建了具有广泛遗传变异罗非鱼育种基础群体。采用人工定向交尾技术,获得了15个以色列红罗非鱼群体内和65个以色列红罗非鱼群体及其他群体间杂交全同胞家系。待家系平均体重5-8 g时进行标记,每个家系随机取样40尾标记个体放入养殖池中,采用逐渐提高盐度驯化至养殖盐度为28,养殖150 d后进行生长性能测试以及杂交和体重生长遗传参数分析。结果显示,在研究的所有群体内和群体间的交配组合中,以色列红罗非鱼品系(♀)与尼罗罗非鱼(♂)杂交的杂交组合(R×N)子一代生长速度最快,优于其他杂交组合,其平均体长、平均体重和绝对增重率分别为24.44 cm、385.23 g和4.94 g/d;ANOVA和LSD多重比较分析结果显示,杂交组合间在体长、体重指标上均达到差异极显著(P<0.01),R×N与除J×R杂交组合外的其他3个杂交和1个群体自繁组子一代两两间存在显著差异(P<0.05)。利用实验构建的80个家系共2496个个体体重数据,考虑家系标记时的平均体重、池塘、雌、雄等因子,建立了遗传参数分析模型,估计体重的遗传力为0.46±0.07,属于中等遗传力。因此,利用本研究收集的罗非鱼基础群体,开展罗非鱼在海水中生长性状选育,具有很大的遗传改良潜力。     

尼罗罗非鱼微卫星标记与主要生长性状的相关性分析

为了筛选到与尼罗罗非鱼生长相关的分子标记,并对这些标记进行准确性鉴定,运用65个微卫星标记对鹭业和番禺2个尼罗罗非鱼群体进行了PCR扩增,再利用SPSS软件一般线性模型(GLM)对这些微卫星位点与尼罗罗非鱼体重等主要生长性状进行了标记性状连锁关联分析。结果表明,鹭业群体中有8个微卫星标记(UNH130,UNH183,UNH911,GM558,UNH211,UNH176,UNH914和UNH974)与主要生长性状显著或极显著相关(P<0.05或P<0.01),其中有2个微卫星标记(UNH914和UNH974)与番禺群体的主要生长性状显著或极显著相关(P<0.05或P<0.01),1个微卫星标记(UNH176)只与体重显著相关(P<0.05)。通过对与生长性状相关标记的基因型和表型值进行多重比较,得到了对体重、体长和体高3种性状有利的基因型或等位基因。发现了对罗非鱼生长性状有显著效应的微卫星位点,为开展罗非鱼的分子标记辅助育种提供了有价值的遗传标记。     

健康养殖专栏

罗非鱼的肥胖症及其防治措施由于长期投喂低蛋白、高脂肪、高糖类和缺维生素的饵料,可造成罗非鱼脂肪代谢障碍,脂肪大量储积,导致鱼体肥胖,抗病能力低下。患肥胖症的罗非鱼是全身性脂肪细胞增生、脂肪浸润,特别是腹腔内的脂肪组织及脏器周围的脂肪组织显著增加。患鱼腹腔内脂肪可达体重的５％～８％。肝脏淡黄色,肝组织高度脂肪变性,肝细胞萎缩,将整块肝组织剪下放在水中,必浮在水面上。而正常肝脏会立即沉入水底。流行与危害：工厂化养殖罗非鱼,密度高,若饵料营养不当,容易发生此病。该病主要危害性成熟个体。患鱼抗病能力低,…     

不同水温下无乳链球菌在尼罗罗非鱼体内的动态分布及其消除规律

本研究以腹腔注射无乳链球菌(Streptococcus agalactiae, WC1535菌株)后的尼罗罗非鱼(Oreochromis niloticus,GIFT strain)为研究对象,研究不同水温下无乳链球菌在尼罗罗非鱼体内的动态分布及消除规律。首先,分析25℃、29℃和33℃3个实验组罗非鱼的感染累积死亡率;其次,对3个实验组罗非鱼进行无乳链球菌的体外分离、培养和计数;然后,分析感染后不同实验组罗非鱼脑、肝脏、脾脏和肾脏组织中无乳链球菌的浓度。结果显示,随着水温的升高罗非鱼的累积死亡率也随之升高,25℃、29℃和33℃组的累积死亡率分别为6.67%、25.56%和78.90%。菌落统计结果显示,随着水温的升高,无乳链球菌在罗非鱼体内的增殖速度加快,同时,单位质量组织(脑、肝脏、脾脏和肾脏)中无乳链球菌的最大载菌量也随之升高。本研究还发现,无乳链球菌在罗非鱼脾脏中的浓度最高,在肾脏中的存活时间最长。综上可知,尼罗罗非鱼感染无乳链球菌后,体内各组织中链球菌的增殖、消除速度均与水温密切相关。本研究为研究无乳链球菌的致病机制奠定基础,也为通过合理调控水温及施药等措施防治尼罗罗非鱼链球菌病的暴发提供科学依据。     

斑点叉尾鮰与罗非鱼混养产量高

为提高精养斑点叉尾鮰的经济效益，美国俄克拉何马洲立大学水产研究站在精养斑点叉尾鮰(400尾／m^3)的水泥池中混养罗非鱼25、50、70尾／m^3与单养斑点又尾鮰的进行比较试验了放养的斑点叉尾鮰平均体重为1.93g，混养的奥利亚罗非鱼平均体重为35.9g。     

罗非鱼湖病毒核蛋白的克隆表达、抗体制备及其组织分布

近年来罗非鱼湖病毒(TiLV)在多个国家流行,对世界罗非鱼养殖业造成严重威胁。中国是罗非鱼第一养殖大国,尽管我国大陆还没有TiLV的正式报道,鉴于吉富罗非鱼是我国重要的罗非鱼养殖品种,其对TiLV的感染特性研究具有重要意义。本实验采用TiLV对吉富罗非鱼进行人工感染,随后在肝脏组织中克隆和测定了TiLV第6片段基因。罗非鱼湖病毒第6片段基因cDNA全长1044 bp,开放读码框(ORF)为954 bp,编码317个氨基酸,预测分子量为36.38 ku;5′非编码区(NCR)为19 bp,3′非编码区(NCR)为972 bp。系统进化树分析表明该蛋白属于TiLV核蛋白(NP)。随后在大肠杆菌中表达和提纯了GST融合NP蛋白,在新西兰大白兔上制备了多克隆抗体。通过酶联免疫吸附实验(ELISA)检测抗体效价为1∶51200,且抗体可特异性识别感染组织中的病毒NP蛋白。对吉富罗非鱼不同组织进行苏木精—伊红(H.E)染色观察,发现肝脏组织坏死并形成合胞体,脾脏部分细胞出现空泡、坏死,含铁血黄素增多,头肾细胞坏死,鳃丝上皮细胞明显解离脱落,鳃小片黏连,脑组织细胞肿大。通过蛋白印迹法(WB)和免疫组化(IHC)对人工感染TiLV的吉富罗非鱼不同组织进行检测,结果显示,NP蛋白在肝脏、脑、体肾和头肾等组织中均有表达,以肝脏组织中表达量最高。为了解吉富罗非鱼对TiLV的免疫反应,通过实时荧光定量PCR(qRT-PCR)测定免疫因子TNF-α和TGF-β在主要免疫器官脾脏和头肾组织中的表达。研究表明,在感染早期(感染后12~24 h),病毒可显著抑制TNF-α和TGF-β在脾脏和头肾中的表达,可能通过抑制宿主这些免疫因子来促进病毒自身早期的复制。本研究将为进一步解读TiLV的致病机理及其高效防控提供理论基础。     

莫荷罗非鱼“广福1号”与其亲本间DNA甲基化的差异分析

为了探讨罗非鱼杂种优势形成过程中基因组DNA甲基化模式的变化,运用甲基化敏感扩增多态技术(methylation sensitive amplified polymorphism,MSAP)分析橙色莫桑比克罗非鱼、荷那龙罗非鱼及其杂交种莫荷罗非鱼"广福1号"的皮肤、肌肉和鳃等11种组织的DNA甲基化水平差异。采用16对引物进行选择性扩增,经聚丙烯酰胺凝胶电泳带型分析结果显示:莫荷罗非鱼"广福1号"及其亲本在不同组织间的甲基化水平存在组织特异性,相同组织不同亲、子代罗非鱼间的甲基化程度亦不同;橙色莫桑比克罗非鱼、荷那龙罗非鱼以及"广福1号"各组织平均总甲基化水平分别为32.21%、38.03%和29.77%,莫荷罗非鱼"广福1号"的甲基化水平低于双亲;与亲本相比,莫荷罗非鱼"广福1号"的甲基化模式除了大多数保持稳定遗传(A、B、C类型分别为19.67%、29.99%、25.42%)之外,24.92%胞嘧啶位点发生去甲基化和超甲基化,且去甲基化位点(E类型,15.73%)多于超甲基化位点(D类型,9.19%)。研究表明,莫荷罗非鱼"广福1号"基因组DNA的低甲基化特征和甲基化模式的重调可能与耐盐杂种优势有关。     

罗非鱼“粤闽1号”及其繁育群体的遗传多样性和遗传关系分析

罗非鱼“粤闽1号”是用尼罗罗非鱼(Oreochromis niloticus)和奥利亚罗非鱼(O. aureus)培育的全雄罗非鱼新品种。采用同工酶电泳技术和线粒体DNA控制区序列分析方法,对罗非鱼“粤闽1号”及其繁育群体的遗传多样性、遗传结构及群体之间的遗传关系进行研究。同工酶电泳结果显示,酯酶(EST)和乳酸脱氢酶(LDH)的酶谱具有组织和群体特异性。肌肉和脾脏中的EST表达量极低,而肝脏中的EST表达量较高,LDH在3种组织中均有较高表达,但酶谱存在差异。在罗非鱼“粤闽1号”及其繁育群体中,共检测到10条EST酶带和5条LDH酶带,多态性位点比例(P)为12.50%~71.43%,平均观测杂合度(Ho)为0.0417~0.6143,Hardy-Weinberg遗传偏离指数(D)为?0.2347~0.9072。线粒体DNA控制区序列分析结果显示,mtDNA D-loop区的碱基组成无显著差异,均呈现出A+T碱基偏向性(63.39%)。在罗非鱼“粤闽1号”及其繁育群体中,共发现20种单倍型,核苷酸多样性指数(Pi)为0~0.0519,奥尼罗非鱼雌鱼(WY1)、尼罗罗非鱼雌鱼(XX)、尼罗罗非鱼雄鱼(XY)和罗非鱼“粤闽1号”(XY2)群体的Pi值(0.0440~0.0519)明显高于超雄尼罗罗非鱼(YY1)、超雄奥尼罗非鱼(YY2)和奥利亚罗非鱼雌鱼(WZ)群体的Pi值(0~0.0009)。各群体之间的遗传分化指数(FST)为?0.0115~0.9963,XY2与WY1群体之间、XX与XY群体之间以及WZ和YY2群体之间的遗传分化不显著(FST<0.05, P>0.05)。XY2群体与尼罗罗非鱼群体(XX群体和XY群体)和奥利亚罗非鱼群体(WZ群体)之间的平均遗传距离分别为0.0639和0.0695。在NJ系统进化树中,XX、XY、YY1和XY2群体聚为一支,WY1、WZ和YY2群体聚为另一支。本研究揭示了罗非鱼“粤闽1号”的生化和分子遗传特征,为其种质鉴定、繁育群体的构建和优良性状的稳定遗传提供理论基础。     

对虾养殖池塘混养罗非鱼对底质有机负荷的作用

采用18个36 m2的围隔进行对虾单养和对虾–罗非鱼混养实验,利用N、S、P综合相对污染指数对单养和混养围隔底质有机负荷进行研究。实验分为6组,每组3个围隔。各围隔放养体长为(0.45±0.01)cm的凡纳滨对虾3 000尾,放养体重为(201±25)g的罗非鱼分别为0(Ⅵ组)、4(Ⅰ组)、8(Ⅱ组)、12(Ⅲ组)、18(Ⅳ组)和24尾(Ⅴ组),放养对虾1个月后再放养罗非鱼。实验期间各围隔均不进行水交换,实验周期为70 d。结果表明,各围隔底质中N、P、S呈现显著上升趋势,但对虾-罗非鱼混养围隔底质中N、P、S的积累量均小于对虾单养围隔。其中,Ⅲ组的N、P、S增长率最小。各组围隔相对污染指数排列如下:Ⅵ(10.78)Ⅴ(8.30)Ⅰ(7.68)Ⅳ(7.40)Ⅱ(6.09)Ⅲ(4.12),其中Ⅲ组的相对污染指数显著小于Ⅵ组(P0.05)。Ⅲ组为本实验的效果最佳组,即混养最佳配比为凡纳滨对虾8.3×105尾/hm2、罗非鱼3 320尾/hm2,罗非鱼均重为(201±25)g/尾。本研究可为对虾–罗非鱼混养中选定合适的养殖容量提供参考。     

Effect of Dietary Fish Meal Replacement by Canola Meal on Growth Performance and Hepatic Intermediary Metabolism of Genetically Improved Farmed Tilapia Strain of Nile Tilapia,Oreochromis niloticus,Reared in Fresh Water

An 8‐wk feeding trial was conducted to evaluate the potential of replacing fish meal with canola meal in experimental diets for genetically improved farmed tilapia (GIFT) strain of Nile tilapia, Oreochromis niloticus (mean initial weight: 20.0 ± 0.62 g, means ± SD), reared in fresh water. Six isonitrogenous (30% crude protein) and isolipidic (10%) diets were formulated with canola meal included at six levels of 0 (control), 11, 22, 33, 44, and 55%, replacing 0, 15, 30, 45, 60, and 75% fish meal, respectively. Growth performance and feed utilization showed no significant differences among the treatments. In general, dietary canola meal supplementation showed significant effect on hepatic composition of tilapia, but not muscle composition. Viscerosomatic index tended to increase with increasing dietary canola meal levels from 0 to 44%, and then declined when dietary canola meal levels further increased from 44 to 55%. Dietary fish meal replacement by canola meal significantly influenced several hepatic enzymatic activities, including succinate dehydrogenase, lactate dehydrogenase, malic dehydrogenase, lipoprotein lipase, and hepatic lipase, suggesting that dietary fish meal replacement by canola meal had significant effects on nutrient metabolism in the liver. Based on the information above, 75% of dietary fish meal could be replaced by canola meal with no effect on growth performance of GIFT strain of Nile tilapia. Use of canola meal in practical diets for GIFT stain of Nile tilapia may allow producers and feed mills to formulate more economical diets.     

Absorption,body distribution,and excretion of dietary zinc by rainbow trout (Salmo gairdneri)

Rainbow trout (Salmo gairdneri) were held in metabolizable energy chambers at Standard Environmental Temperature (15°C) for 72h following a single feeding of a semi-purified test diet containing tracer quantities of a radioisotope of zinc (⁶⁵Zn) and different combinations of dietary calcium level and zinc source. Gill wastes, urine, and feces were separately collected. After 72h, the fish were killed, and samples of the following tissues removed: eyes, skin, muscle, blood, bone, liver, bile, kidney, gill, spleen, stomach, pyloric caeca, intestine, gonad, and remaining carcass. Radioactivity in the tissues and wastes was determined and the body distribution of the ingested zinc was quantified. Approximately 58% of the administered dose of⁶⁵Zn was recovered. Of the recovered dose, 43.2% was present in the gastro-intestinal tract, 27% in the feces, 14% in the gill water, 16% in the body of the fish, and less than 1% in the urine. Of individual tissues, the gill, liver, kidney, and spleen had concentrations of⁶⁵Zn higher than blood, while the remaining tissues had lower concentrations. Body and tissue levels were increased but not significantly by feeding⁶⁵Zn as an amino acid chelate, compared to feeding as inorganic⁶⁵Zn, while dietary calcium level had no effect. The results of this study indicate that the gills play a major role in excretion of dietary zinc, while the urine plays a minor role.     

Effects of α‐lipoic acid on growth performance,body composition,antioxidant profile and lipid metabolism of the GIFT tilapia (Oreochromis niloticus) fed high‐fat diets

The wide use of lipid as a non‐protein energy substitute has led to lipid metabolic problems in cultured tilapia. Therefore, studies that reduce the effects of high‐fat diets in genetically improved farmed tilapia (GIFT) are required. This study evaluated the optimum level and effects of dietary α‐lipoic acid (α‐LA) on growth performance, body composition, antioxidant capacity and lipid metabolism of GIFT tilapia. The basal diet (120 g/kg lipid) was supplemented with six concentrations of α‐LA at 0 (control), L300, L600, L900, L1200 and L2400 mg/kg diet to make the experimental diets, which were fed to GIFT tilapia juveniles (initial body weight: 0.48 ± 0.01 g) for 8 weeks. The weight gain of fish improved significantly in the L300 than other dietary treatments. The intraperitoneal fat index and lipid content of fish fed on the L2400 diet decreased significantly than those fed on the control diet. The activities of superoxide dismutase and glutathione peroxidase (GSH‐Px) in serum and liver were significantly higher in fish fed on the L300 diet than the control. The reduced GSH content of fish fed on the L300 in serum and liver was significantly higher than those fed on control diet. The malondialdehyde content in serum and liver was significantly lower in L300 than in the control. The adipose triglyceride lipase gene was significantly up‐regulated in fish fed on the L2400, but the diacylglycerol acyltransferase 2 gene was down‐regulated in adipose. The liver‐type fatty acid‐binding protein gene in the liver was significantly up‐regulated in fish fed on the L300 and L600 diets. Moreover, the acyl‐coenzyme A oxidase gene in liver was significantly up‐regulated in fish fed on the L300, L600, L900 and L1200 diets. Polynomial regression analysis indicated that 439–528 mg/kg α‐LA is an appropriate dosage in high‐fat diet to improve growth performance and relieve lipid oxidative damage by accelerating lipid catabolism and reducing lipid synthesis in GIFT tilapia.     

一种虹彩病毒感染大菱鲆的病理学研究

对我国虹彩病毒感染的大菱鲆Scophthalmus maximus进行的组织病理和超微病理学研究发现,该病典型的病理学特点是在病鱼的脾脏、肾脏、肠、肝脏、鳃、心脏和皮肤等器官组织内出现嗜碱性的肿大细胞。病毒感染导致患病大菱鲆多个器官组织发生了不同程度的病理变化,其中以脾脏组织的病理变化最为显著,表现为造血组织的严重坏死。此外,肾脏造血组织发生坏死、肠固有膜和黏膜下层出血和水肿、肝细胞水样变性、心肌局灶性坏死以及皮肤真皮层出血并伴有水肿和炎性渗出也是该病常见的组织病理学变化。超微病理研究表明,肿大细胞内有虹彩病毒粒子存在。病毒分布于受感染细胞的胞质、组织间隙以及血管腔内。受感染细胞出现线粒体和内质网等细胞器肿胀、崩解等细胞病理变化。研究认为,病毒感染造成皮下组织血管损伤出血,是虹彩病毒感染的大菱鲆发生＂红体病＂的原因所在。虹彩病毒感染所致的机体严重贫血是患病大菱鲆死亡的主要原因,而主要器官组织的病变使得病鱼器官功能衰竭则可加速鱼的死亡。     

Macro and Micro Mineral Levels in the Tissues of Menhaden Fish

Various tissues of menhaden fish were analyzed for macro and micro minerals. Tissues selected were gill, heart, intestine, kidney, liver, muscle, spleen, and stomach. Phosphorus, calcium, magnesium, sodium, manganese, and zinc were found to be most concentrated in the gill. Potassium, iron, and boron were least concentrated in the gill. Liver contained the highest concentration of copper, selenium and boron. The stomach was the highest in potassium and lowest in phosphorus. Sodium and selenium concentrations were lowest in the muscle. Mercury concentrations were approximately 2 mg/g dry matter in all tissues     

低温驯化下4种不同品系罗非鱼血清皮质醇与免疫相关指标的变化

选取4种不同品系罗非鱼, 分别为吉富罗非鱼(Oreochromis niloticus)、奥尼罗非鱼(O. niloticus×O. aureus)、红罗非鱼(O. nilotica♂× O. mossambica♀)和奥利亚罗非鱼(O. aureaus)。在26℃水温下饲养3周后, 选取规格基本一致的罗非鱼(体质量50.73 g±4.23 g)进行低温驯化实验。水温以3℃/d的速度从26℃降至8℃, 分别于水温为26℃、20℃、14℃和8℃时进行采样, 比较不同驯化阶段4种不同品系罗非鱼血清皮质醇和免疫相关指标的变化规律。结果表明, 与26℃时的免疫指标相比, 水温降至8℃时, 吉富与红罗非鱼血清皮质醇水平显著升高; 然而血清C3、C4、IgM以及头肾C型溶菌酶mRNA水平显著下降(P<0.05), 血清中高皮质醇水平对鱼体的免疫产生了抑制作用。水温为8℃时, 奥尼罗非鱼血清皮质醇、IgM和补体C3以及头肾抗菌肽mRNA水平显著升高; 奥利亚血清皮质醇、C4和IgM以及头肾C型溶菌酶mRNA水平与26℃时相比无显著差异, 然而血清溶菌酶与C3水平降低。驯化实验结束后, 比较了4种不同品系罗非鱼在8℃水温下48 h内的累积死亡率。吉富与红罗非鱼组累积死亡率较高, 分别达到43.3%和40.0%; 奥尼罗非鱼其次, 为23.3%; 奥利亚罗非鱼最低, 为20.0%。较高的血清IgM和头肾溶菌酶和抗菌肽mRNA水平可能有助于提高奥尼和奥利亚罗非鱼的抗低温应激能力, 增加低温时的成活率。本研究通过分析4种品系罗非鱼不同驯化阶段血清皮质醇和免疫相关指标, 探讨不同品系罗非鱼在低温驯化过程中的免疫保护机制, 旨在为下一步抗低温新品系罗非鱼的选育提供理论依据。

     

淋巴囊肿病毒27.8 ku受体蛋白在牙鲆组织中的分布

应用抗牙鲆淋巴囊肿病毒(lymphocystis disease virus,LCDV)受体蛋白(27.8 ku)的单克隆抗体(2G11和3D9)定位LCDV受体蛋白在牙鲆组织中的分布。通过对牙鲆外周血、白细胞、鳃、胃、肠、表皮、肝脏、头肾、体肾、脾、性腺、脑、心脏等进行LCDV受体蛋白的间接免疫荧光与免疫组织化学定位观察,发现在牙鲆外周血白细胞的细胞膜、鳃上皮细胞、表皮、胃黏膜上皮细胞顶端、肠上皮细胞、肝细胞、脾表层结缔组织细胞及头肾后端的肾小管上皮细胞内均有较强的阳性信号,表明这些部位分布有LCDV的27.8 ku受体蛋白,但在体肾、性腺、脑、心脏及外周血红细胞中未观察到阳性信号。推测LCDV通过与鳃、表皮及消化道上皮的受体结合进入牙鲆体内,通过与外周血白细胞上的受体结合侵染白细胞而进入血液循环,进而感染肝脏、脾脏、头肾等器官。     

Preliminary study to evaluate the effects of dietary bile acids on growth performance and lipid metabolism of juvenile genetically improved farmed tilapia (Oreochromis niloticus) fed plant ingredient‐based diets

A 9‐week feeding experiment was conducted to investigate the effects of dietary bile acids (BAs) on juvenile genetically improved farmed tilapia (GIFT) (Oreochromis niloticus) based on the evaluations of growth performance and parameters relevant to lipid metabolism. Each of five vegetable protein‐based diets containing BAs at a level of 0, 0.05, 0.15, 0.45 or 1.35 g/kg diet was fed to three replicates with 40 fish (8.2 g per fish). The results showed that weight gain (WG) increased significantly with the increase in BAs from 0 to 0.15 g/kg diet and then decreased significantly at a higher BA supplementation. Dietary BAs significantly reduced the crude lipid content in the whole body, muscle and liver tissue of GIFT. Fish fed diet with 1.35 g BAs/kg diet developed serious nuclear migration and vacuolization in hepatocytes. Gall bladder appeared to contain white solid and has fragile capsules. Dietary BA supplementation had significant effects on serum biochemical indices and activities of lipid metabolism enzymes in liver and intestine. In conclusion, dietary bile acid supplementation (0.15 g/kg) can facilitate the lipid metabolism and therefore promote the growth of tilapia. However, overdosed dietary BAs induced gallstone development, disrupted lipid metabolism and depressed the growth performances of GIFT.