养殖暗纹东方鲀鱼体的生化组成及营养需求初探

本文对池塘养暗纹东方 (Fuguobscurus)的一龄鱼 (体重 4 0 - 80g)、二龄鱼 (体重 2 0 0 - 30 0g)鱼体的生化组成进行了比较分析。结果表明 :二龄鱼的粗蛋白含量低于一龄鱼 ,而粗脂肪含量明显高于一龄鱼 ,在必需氨基酸中 ,二龄鱼除了赖氨酸、精氨酸含量明显高于一龄鱼外 ,其余氨基酸的含量几乎都低于一龄鱼 ,且它们的组成比例较接近 ,在非必需氨基酸中 ,一龄鱼、二龄鱼均以谷氨酸的含量为最高 ,分别占非常必需氨基酸的 2 6 .5 4%和 2 6 .6 9% ;在脂肪酸的组成上 ,二龄鱼的单烯酸的含量都比一龄鱼高 ,尤其是C18∶1含量比一龄鱼高12 .2 3% ,而饱和脂胶酸、多烯酸的含量则一龄鱼比二龄鱼含量高 ,尤其是DHA的含量比二龄鱼高 4 .4 3% ;在测定的 14种矿物元素中 ,二龄鱼的Ca、Zn的含量明显高于一龄鱼外 ,其余元素的含量略低于或接近一龄鱼     

养殖暗纹东方Tun鱼体的生化组成及营养需求初探

本文对池塘养暗纹东方鲀(Fugu obscurus)的一龄鱼(体重40-80g)、二龄鱼(体重200-300g)鱼体的生化组成进行了比较分析.结果表明二龄鱼的粗蛋白含量低于一龄鱼,而粗脂肪含量明显高于一龄鱼,在必需氨基酸中,二龄鱼除了赖氨酸、精氨酸含量明显高于一龄鱼外,其余氨基酸的含量几乎都低于一龄鱼,且它们的组成比例较接近,在非必需氨基酸中,一龄鱼、二龄鱼均以谷氨酸的含量为最高,分别占非常必需氨基酸的26.54%和26.69%;在脂肪酸的组成上,二龄鱼的单烯酸的含量都比一龄鱼高,尤其是C181含量比一龄鱼高12.23%,而饱和脂胶酸、多烯酸的含量则一龄鱼比二龄鱼含量高,尤其是DHA的含量比二龄鱼高4.43%;在测定的14种矿物元素中,二龄鱼的Ca、Zn的含量明显高于一龄鱼外,其余元素的含量略低于或接近一龄鱼.     

塘养一龄与二龄暗纹东方Tun鱼体的生化组成

对池塘养殖暗纹东方Ｔｕｎ（Ｆｕｇｕ ｏｂｓｃｕｒｕｓ）的一龄鱼（体重４０～８０ｇ）、二龄鱼（体重２００～３００ｇ）鱼体的生化组成进行了分析。结果表明：二龄鱼的粗蛋白含量低于一龄鱼,而粗脂肪含量则明显高于一龄鱼;在必需氨基酸中,二龄鱼除了赖氨酸、精氨酸含量明显高于一龄鱼外,其余氨基酸的含量几乎都低于一龄鱼,且它们的组成比例较接近,在非必需氨基酸中,一龄鱼、二龄鱼均以谷氨酸的含量为最高,分别占非必要氨基酸的２６．５４％和２６．６９％;在脂肪酸的组成上,二龄鱼的单烯酸的含量都比一龄鱼高,尤其是Ｃ１８：１含量比一龄鱼高１２．２３,而饱和脂肪酸、多烯酸的含量则一龄鱼比二龄鱼含量高,尤其是ＤＨＡ的含量比二龄鱼高４．４３％;在测定的１４种矿物元素中,二龄鱼的Ｃａ、Ｚｎ的含量明显高于一龄鱼外,其余元素的含量略低于或接近一龄鱼。     

野生与养殖光唇鱼肌肉营养组成与评价

对采自浙江省新昌县的野生(平均质量15.3g)和养殖(平均质量14.9g)光唇鱼肌肉营养组成分别进行了测定和评价。野生光唇鱼肌肉蛋白质含量为16.62%,脂肪2.66%,水分80.73%,灰分0.92%;养殖光唇鱼肌肉蛋白质含量为16.51%,脂肪2.51%,水分80.65%,灰分0.94%;野生光唇鱼的水分、蛋白质和脂肪含量均较养殖光唇鱼略高。共检测到17种氨基酸,其中必需氨基酸8种,风味氨基酸4种。野生组的氨基酸总量显著高于养殖组;必需氨基酸的总量也高于养殖组。与养殖光唇鱼相比,野生光唇鱼肌肉中苏氨酸、亮氨酸及含硫氨基酸含量较高。以氨基酸评分为标准,光唇鱼肌肉的第一限制氨基酸是赖氨酸,第二限制性氨基酸为缬氨酸;以化学评分为标准,说明光唇鱼肌肉必需氨基酸组成相对平衡且含量丰富,是一种较为平衡的优质蛋白质。共检出22种脂肪酸,光唇鱼肌肉中所含饱和脂肪酸有9种;不饱和脂肪酸共有14种,其中单不饱和脂肪酸6种,多不饱和脂肪酸8种;饱和脂肪酸中C 16:0含量最大;而不饱和脂肪酸中C 16:1和C 18:2含量最高。多不饱和脂肪酸中二十碳五烯酸(C 20:5)含量为10.20%;二十碳六烯酸(C 22:6)含量为9.18%,在淡水鱼中是较高的,是一种优质的淡水食用鱼类。     

北方寒区2龄和3龄雄性中华绒螯蟹成蟹可食率、色泽及品质比较

为开发中华绒螯蟹(Eriocheir sinensis)新种质并阐述其品质特征, 本研究以北方寒区 2 龄雄性成熟中华绒螯蟹(简称 2 龄蟹)为对照, 探究 3 龄雄性成熟中华绒螯蟹(简称 3 龄蟹)的可食率、色泽、常规营养品质、脂肪酸、游离氨基酸和矿物质元素差异, 为 3 龄蟹新种质开发和利用提供重要的判断依据。结果表明; 9 月 15 日 2 龄蟹肝胰腺指数(HSI)极显著高于 3 龄蟹(P＜0.01), 而出肉率(MY)则显著低于 3 龄蟹(P＜0.05)。2 龄蟹与 3 龄蟹相比, 头胸甲和肝胰腺湿样 L* , 头胸甲和肝胰腺干样 a* 存在显著性差异(P＜0.05)。2 龄蟹肝胰腺中粗脂肪含量显著高于 3 龄蟹 (P＜0.05), 而性腺系统和肌肉中粗蛋白含量则高于 3 龄蟹。就脂肪酸而言, 2 龄蟹肝胰腺、性腺系统和肌肉中 DHA 和 DHA/EPA 含量均高于 3 龄蟹, 而 ARA 则低于 3 龄蟹。肌肉中脂肪酸显著性差异项(5 项)明显高于肝胰腺(1 项) 和性腺系统(1 项)。就游离氨基酸而言, 2 龄蟹肝胰腺、性腺系统和肌肉中总必需氨基酸(ΣEFAA)、总游离氨基酸 (ΣFAA)均高于 3 龄蟹。性腺系统中显著性差异项(6 项)明显高于肝胰腺(0 项)和肌肉(2 项)。2 龄蟹肝胰腺和性腺系统中谷氨酸(Glu)、总鲜味氨基酸(ΣTUV)高于 3 龄蟹, 而肌肉中则低于 3 龄蟹。就矿物质元素而言, 2 龄蟹 3 种可食组织中 Na、K、Ca、Mg 和 Cu 元素含量均低于 3 龄蟹。肝胰腺中矿物质元素显著性差异项(5 项)明显高于性腺系统 (1 项)和肌肉(2 项)。综上所述, 2 龄蟹大部分常规营养成分、脂肪酸、游离氨基酸指标均优于 3 龄蟹, 但可食率参数、大部分矿物质元素含量则明显低于 3 龄蟹。整体来看, 2 龄和 3 龄雄蟹各有优势, 均具有较高的营养价值。     

俄罗斯鲟肌肉营养成份的分析

采用生化分析方法对工厂化养殖的1龄和2龄俄罗斯鲟的肌肉营养成份进行检测。结果表明,1龄鱼的水分含量为80.84%,蛋白质含量为16.10%,脂肪含量为2.14%,灰分含量为0.92%;2龄鱼的水分含量为79.96%,蛋白质含量为15.00%,脂肪含量为4.08%,灰分含量为1.26%;1龄俄罗斯鲟肌肉中蛋白质含量高于2龄,脂肪含量低于2龄,且差异均显著;1龄和2龄俄罗斯鲟肌肉蛋白质中都含有18种氨基酸,平均含量分别为15.60%、14.46%,其中8种人体必需氨基酸平均含量分别为6.30%、5.95%,4种呈味氨基酸的平均含量分别为6.70%、6.26%;1龄和2龄俄罗斯鲟肌肉中都包含有9类脂肪酸,脂肪酸总量及各类脂肪酸含量都非常接近。     

松浦镜鲤与德国镜鲤选育系1、2龄鱼的生长性能、抗病力及抗寒力对比试验

2005到2008四年期间用池塘进行了松浦镜鲤（SP）与德国镜鲤选育系F4（DJ）1、2龄鱼的生长性能、抗病能力及抗寒能力的测定。结果表明：SP1、2龄鱼在生长性能、抗病能力及抗寒能力方面均要优于同龄的DJ。生长性能方面，SP1龄鱼瞬时体重增长率（4．56％）、相对体重增长率（111．14％）和体重净增重（213．53g）分别比DJ快630％、31.9％、34．7％；2龄鱼瞬时体重增长率（1．62％）、相对体重增长率（6．38％）和体重净增重（1285.24g）分别比DJ提高了2．86％、8А3％、45．23％。抗病力方面，1龄鱼的饲养成活率SP（96．95％）比DJ提高了13.66％；2龄鱼SP（96．44％）比DJ提高了6A8％。越冬抗寒方面，1龄鱼的越冬成活率SP（95．85％）比DJ提高了8．86％；2龄鱼SP（98．84％）比DJ提高了3．36％。     

丁鱥不同生长阶段肌肉脂肪酸和微量营养元素的比较

对丁鱥不同生长阶段鱼体肌肉中脂肪酸组成及微量营养元索含量进行了比较。结果表明：丁鱥不同生长阶段肌肉中的脂肪酸含量及组成有明显差异。脂肪酸总量、不饱和脂肪酸总量和饱和脂肪酸总量，亲鱼均高于幼鱼和成鱼，成鱼均高于幼鱼；不饱和脂肪酸／饱和脂肪酸总量，成鱼和亲鱼均高于幼鱼；同时，成鱼和亲鱼肌肉中高度不饱和脂肪酸花生三烯酸、花生四烯酸、二十二碳五烯酸和EPA、DHA含量明显高于幼鱼肌肉。成鱼和亲鱼肌肉中微量营养元素Fe和Mn含量显著低于幼鱼（P〈0．05）；亲鱼肌肉中Zn含量显著低于成鱼和幼鱼（P（0．05），成鱼显著高于幼鱼（P（0．05）；亲鱼肌肉中Cu含量显著低于成鱼和幼鱼（P〈0．05）。     

团头鲂优势配套系1龄至2龄阶段生长性能分析

为进一步验证团头鲂配套系间杂交子代的生长优势,以团头鲂"浦江1号"选育系F_(12)为对照组,通过开展同池养殖试验,分析了优势配套组合(优势组)——雌核发育群体F_4(♀)×"浦江1号"F_(11)(♂)子代在1龄至2龄阶段的生长性能。结果显示:在1龄阶段,优势组试验鱼的终末体质量比对照组高12.54%(P0.05),特定增重率比对照组高2.47%(P0.05);在2龄阶段,优势组试验鱼的相对增重率比对照组高8.97%(P0.05),特定增重率比对照组高4.62%(P0.05)。优势组在1龄和2龄阶段的体质量变异系数均低于对照组(P0.05)。与对照组相比,优势组在1龄阶段成活率略低,而在2龄阶段成活率略高(P0.05)。结果表明,团头鲂优势配套系在1龄和2龄阶段有明显的生长优势,但在整齐度和成活率方面与团头鲂"浦江1号"选育系F_(12)没有显著差异。     

斑鳠肌肉营养成份分析

斑鱼萑又蛋白质含量为16.89%,低于黄鳝,与斑点叉尾鱼回、乌鳢相当,高于黄颡鱼、鲫、鳙;其脂肪含量为2.70%,与斑点叉尾鱼回、黄颡鱼、中华倒刺鱼巴相当,明显高于黄鳝、乌鳢、鲫、鳙;其DHA和EPA含量较高;16种必需氨基酸含量为6.86 g/kg,较黄鳝、乌鳢、黄颡鱼略低,5种鲜味氨基酸含量为3.15 g/kg。     

Rare serotype occurrence and PFGE genotypic diversity of Streptococcus agalactiae isolated from tilapia in China

Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China.     

Growth hormone (GH) and reproduction: a review

Interaction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations.     

Purification and partial characterization of GtHs (cfLH and cfFSH) from Indian walking catfish (Clarias batrachus) (L.) and development of a homologous ELISA for cfLH

Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL^?1 (1.25 ng well^?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation.     

Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection

Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg^?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality).     

Imported ornamental fish are colonized with antibiotic‐resistant bacteria

There has been growing concern about the overuse of antibiotics in the ornamental fish industry and its possible effect on the increasing drug resistance in both commensal and pathogenic organisms in these fish. The aim of this study was to carry out an assessment of the diversity of bacteria, including pathogens, in ornamental fish species imported into North America and to assess their antibiotic resistance. Kidney samples were collected from 32 freshwater ornamental fish of various species, which arrived to an importing facility in Portland, Oregon from Colombia, Singapore and Florida. Sixty‐four unique bacterial colonies were isolated and identified by PCR using bacterial 16S primers and DNA sequencing. Multiple isolates were identified as bacteria with potential to cause disease in both fish and humans. The antibiotic resistance profile of each isolate was performed for nine different antibiotics. Among them, cefotaxime (16% resistance among isolates) was the antibiotic associated with more activity, while the least active was tetracycline (77% resistant). Knowing information about the diversity of bacteria in imported ornamental fish, as well as the resistance profiles for the bacteria will be useful in more effectively treating clinical infected fish, and also potential zoonoses in the future.     

Effect of iodophor disinfection of non‐hardened Salmo trutta eggs on their bacterial and fungus load

This study investigated the efficiency of iodophor disinfection (135 ppm active iodine for 15–30 min) of non‐hardened Salmo trutta eggs against different groups of bacteria and against fungus. Egg samples were taken from non‐disinfected and from disinfected eggs, microorganisms were cultured on specific nutrient media and their mass was measured by turbidimetric methods. Bacteria and fungus mass of non‐hardened eggs could be reduced but not eliminated by iodophor disinfection with 135 ppm active iodine for 15 min. The extent of reduction was 47–65% (Experiment 1). The efficiency of disinfection increased with disinfection time as the reduction in bacteria and fungus mass was 40–55% after 15 min and 58–74% after 30 min (Experiment 2). Disinfection efficiency of iodophor solution diluted in water (reduction 49–57%) and of iodophor solution diluted in sodium chloride solution iso‐osmolar to the oocytes (reduction 52–61%) was similar (Experiment 3). The reduction in bacteria and fungus mass was persistent as it was 39–72% lower in embryos deriving from disinfected eggs than in embryos deriving from non‐disinfected ones (Experiment 4). In conclusion, the tested disinfection method is inadequate to eliminate pathogens completely but it could positively influence immune defence of eggs and embryos.     

Nitrogenous waste excretion and accumulation of urea and ammonia inChalcalburnus tarichi (Cyprinidae), endemic to the extremely alkaline Lake Van (Eastern Turkey)

The endemic, anadromous cyprinidChalcalburnus tarichi is the only fish species known to occur in alkaline Lake Van (Eastern Anatolia, Turkey). EightC. tarichi were maintained individually in Lake Van water (17 – 19°C; pH 9.8; 153 mEq·I^–1 total alkalinity; 22 total salinity) and tank water samples analyzed for 24 h in 2 to 4 h intervals. At zero time, < 1µM ammonia was present and urea was undetectable in the tank water; at 24 h, total ammonia and urea made up 114±32 and 35±25µM, respectively. Over the experimental period, ammonia-N and urea-N excretion averaged 1041±494 and 607±169moles·kg^–1 fish·h^–1, respectively. The extent of urea excretion was highly variable between specimens. Uric acid excretion was not detectable.Urea was present at high concentrations in all tissues and plasma (25 – 35moles·g^–1·ml^–1) of freshly caughtC. tarichi; total ammonia content of the tissues was by a factor of 1.9 (liver) to 3.0 (brain) lower. High arginase activity (2.4±0.2 U·min^–1·g^–1) was detected in the liver ofC. tarichi but ornithine carbamoylphosphate transferase, a key enzyme of the ornithine-urea-cycle, was absent. Ureagenesis is likely through degradation of arginine and/or uricolysis. High glutamine synthetase activity (11±0.6 U·min^–1·g^–1) and low ammonia content in brain suggest that, like other teleosts,C. tarichi has an efficient ammonia detoxification in the brain, but in no other tissue.Nitrogenous waste excretion at alkaline pH is discussed. The ability ofC. tarichi to excrete high levels of ammonia at extremely alkaline pH is unique among teleosts studied so far. The mechanism of ammonia excretion under Lake Van conditions remains to be elucidated.     

Influence of the antibacterial herbs, Solanum trilobatum, Andrographis paniculata and Psoralea corylifolia on the survival, growth and bacterial load of Penaeus monodon post larvae

The indiscriminate use of antibiotics and chemicals in shrimp hatcheries has led to biomagnification and that in turn could lead to rejection of a whole consignment. The application of the bioencapsulation technique as a tool for curative treatment in shrimp larvae was investigated. Herbs having antibacterial properties such as Solanum trilobatum, Andrographis paniculata and Psoralea corylifolia (methanolic extracts) were bioencapsulated in Artemia and fed to Penaeus monodon post larvae PL 1–25. The post larvae were reared in a medium inoculated with pathogenic bacteria such as Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and Vibrio sp. Post larvae reared in the non-inoculated water and fed with non-enriched Artemia exhibited 90% survival, highest specific growth rate (12.43%) and reduced bacterial load. P. monodon reared in the bacterial inoculated water and fed with the non-enriched Artemia exhibited the lowest survival (10–30%), specific growth rate (8.42–9.1%) and increased bacterial load (2.86 × 10³ to 3.76 × 10⁵ cfu/g). The methanolic extracts of the herbs helped to increase survival and specific growth rate and reduced bacterial load in the P. monodon culture system. Among the three herbal extracts, P. corylifolia enriched Artemia fed post larvae showed the tendency to higher survival (>50%), growth rate (11.5 averaged) and low bacterial load (1.12 × 10⁵ cfu/g). This revised version was published online in August 2006 with corrections to the Cover Date.