几种蟹类的比较鉴别

华绒螯蟹,日本绒螯蟹,直额绒螯蟹,狭额绒螯蟹均属于绒螯蟹属的4个种,其形态鉴别如下:     

中国大陆沿海六水系绒螯蟹_中华绒_省略__群体亲缘关系_生化遗传差异分析

采用聚丙烯酰胺凝胶电泳分析比较了分布于我国大陆沿海 6个主要水系的两种绒螯蟹 (中华绒螯蟹、日本绒螯蟹 )群体间的生化遗传差异。结果发现 ,(1)辽河、黄河、长江和瓯江中华绒螯蟹群体间的生化遗传差异不显著 ,四个群体间的遗传距离D =0 .0 0 0 6～ 0 .0 0 53,属种内群体间差异。 (2 )珠江和南流江日本绒螯蟹群体间的生化遗传差异也不显著 ,两个群体间遗传距离D=0 .0 0 0 7,尚未达到亚种分化水平。 (3)辽河、黄河、长江和瓯江中华绒螯蟹与珠江和南流江日本绒螯蟹在SOD同工酶表型上有明显差异 ,SOD - 2位点仅在辽河、黄河、长江和瓯江中华绒螯蟹中表达 ,而SOD - 4位点仅在珠江和南流江日本绒螯蟹中表达 ,这些可作为中华绒螯蟹与日本绒螯蟹群体区分的生化遗传标志。辽河、黄河、长江和瓯江中华绒螯蟹群体同珠江和南流江日本绒螯蟹群体间的遗传距离较大 ,D =0 .0 72 1～ 0 .0 74 7。 (4 )聚类分析表明 ,在我国大陆沿海水系分布的绒螯蟹可分为两大类群 ,辽河、黄河、长江和瓯江水系的绒螯蟹属北方类群 ,即中华绒螯蟹 ;珠江和南流江的绒螯蟹属南方类群 ,即日本绒螯蟹。     

中国大陆沿海六水系绒螯蟹（中华绒螯蟹和日本绒螯蟹）群体亲缘关系：？…

采用聚丙烯酰胺凝胶电泳分析比较了分布于我国大陆沿海６个主要水系的两种绒螯蟹（中华绒螯蟹、日本绒螯蟹）群体间的生化遗传差异。结果发现：（１）辽河、黄河、长江和瓯江中华绒螯蟹群体间的生化遗传差异不显著,国个群体间的遗传距离Ｄ＝０．０００６～０．００５３,属种内群体间差异。（２）珠江和南流江日本绒螯蟹群体间的生化遗传差异也不显著,两个群体间遗传距离Ｄ＝０．０００７,尚未达到亚种分化水平。（３）辽河、黄河     

河蟹池塘越冬技术

河蟹是我国特产,又称螃蟹、大闸蟹和毛蟹等,主要分布在中国东部各海域沿岸及通海的河流、湖泊中。在分类学上属甲壳纲、十足目、方蟹科、绒螫蟹属。该属有中华绒螯蟹、日本绒螯蟹、狭额绒螯蟹和直额绒螯蟹四种。后两种个体小,经济价值不大;而前两种个体大,肉质鲜美,经济价值高。因此,河蟹实际上是中华绒螯蟹和日本绒螯蟹的总称。河蟹的肉质鲜嫩,是深受人们喜爱的一味食品。在北方,由于当年生产的河蟹苗不能长到商品蟹规格,扣蟹要经过越冬后,第二年秋天才能达到商品蟹规格。另外,秋季正是大部分河蟹收获的季节,价格较低,若要经过越冬,在春节或第二年开春后出售,价格就会很高,所以说一般的河蟹养殖户都会采用越冬的方式。     

中国大陆沿海六水系绒螯蟹（中华绒螯蟹和日本绒螯蟹）群体亲缘关系：R …

用４８个具有丰富多态性的１０碱基随机引物对辽河、黄河、长江、瓯江、珠江和南流江的中华绒螯蟹和日本绒螯蟹的６个群体进行ＲＡＰＤ分析。结果发现：（１）两个引物具有群体特异性带,其中Ｚ２扩增的８８０ｂｐ片段为珠江蟹和南流江蟹群体中所特有,而７００ｂｐ片段为长江蟹、辽河蟹、黄河蟹和瓯江蟹所特有,可作为区别日本绒螯蟹和中华绒螯蟹的分子遗传标记;（２）Ｏｐｐ１７扩增的９４７ｂｐ片段的出现频率,在长江、黄河和辽     

中华绒螯蟹的同属种类及其英文名称

余述绒螯蟹属中三个公认种的主要特征和地理分布,并对中华绒螯蟹目前使用的几个英文名称的合理性和取舍问题加以讨论。     

中华绒螯蟹、日本绒螯蟹及其杂交种性腺发育和生化组成的比较

研究了中华绒螯蟹(Eriocheir sinensis)、日本绒螯蟹(E.japonica)及其杂交种成蟹性腺指数、肝胰腺指数、出肉率、总可食率及其常规生化成分,结果显示:(1)中华绒螯蟹的精巢指数显著高于其它两种群蟹,但其肝胰腺指数、出肉率和总可食率均无显著差异;中华绒螯蟹的卵巢指数也显著高于日本绒螯蟹和杂交蟹,而杂交蟹的肝胰腺指数显著高于其它两种群蟹。(2)中华绒螯蟹、日本绒螯蟹和杂交种精巢中水分、蛋白和脂肪含量分别最低,日本绒螯蟹精巢中碳水化合物含量最高;杂交种肝胰腺蛋白、脂肪和碳水化合物含量均最高,日本绒螯蟹肌肉中脂肪含量显著低于其它两种群。(3)日本绒螯蟹卵巢水分含量显著高于其它两种群蟹,蛋白、脂肪和碳水化合物含量显著低于其它两种群;日本绒螯蟹肝胰腺的水分和蛋白含量最高,但脂肪含量最低,杂交种肝胰腺中脂肪含量最高、水分含量最低;日本绒螯蟹肌肉中的水分含量最高,其它生化成分含量最低;中华绒螯蟹肌肉的水分含量最低,其它生化成分含量最高。整体上,中华绒螯蟹具有早熟特性,不同种群绒螯蟹性腺中的主要生化成分含量可能与其发育阶段有关,杂交蟹肝胰腺中脂肪含量较高,日本绒螯蟹肌肉中脂肪含量较低。     

基于COⅠ序列绒螯蟹属DNA条形码和遗传多样性研究

对绒螯蟹属的中华绒螯蟹如东和七里海群体、日本绒螯蟹、合浦绒螯蟹及狭颚绒螯蟹共80条线粒体COⅠ片段进行扩增和测序,并与GenBank中绒螯蟹属的台湾绒螯蟹2条和近方蟹属的绒毛近方蟹19条COⅠ基因序列进行联配分析。结果显示,101条序列包含44种单倍型,序列组成表现明显的碱基偏倚性。中华绒螯蟹如东、七里海群体与日本绒螯蟹间的遗传距离分别为1.210%和1.078%,明显低于COⅠ基因DNA条形码鉴别种的遗传距离为2%的阈值,表明中华绒螯蟹和日本绒螯蟹为同一物种;而合浦绒螯蟹与中华绒螯蟹如东和七里海群体及与日本绒螯蟹的遗传距离分别为4.823%、5.101%以及5.011%,明显大于2%的鉴别阈值,说明合浦绒螯蟹为独立的种。以绒毛近方蟹为外群,基于群体内及群体间的遗传距离构建的邻接树显示,中华绒螯蟹与日本绒螯蟹聚在一起,合浦绒螯蟹则聚成单系。本文测序的5个群体除狭颚绒螯蟹外,其余均具有遗传多样性,单倍型多样性为0.593±0.144~0.779±0.068,核苷酸多样性为0.00156~0.01336;此外,中华绒螯蟹如东群体与日本绒螯蟹、合浦绒螯蟹和中华绒螯蟹七里海群体分别共享单倍型H1、H2和H3,说明这些蟹类可能有种质资源混杂或是遗传污染的现象。     

中国大陆沿海六水系绒螯蟹_中华绒_省略__群体亲缘关系_RAPD指纹标记

用 4 8个具有丰富多态性的 10碱基随机引物对辽河、黄河、长江、瓯江、珠江和南流江的中华绒螯蟹和日本绒螯蟹的 6个群体进行RAPD分析。结果发现 :(1)两个引物具有群体特异性带 ,其中Z2扩增的 880bp片段为珠江蟹和南流江蟹群体中所特有 ,而 70 0bp片段为长江蟹、辽河蟹、黄河蟹和瓯江蟹所特有 ,可作为区别日本绒螯蟹和中华绒螯蟹的分子遗传标记 ;(2 )Opp17扩增的 94 7bp片段的出现频率 ,在长江、黄河和辽河群体显著地从南到北递减 ,长江蟹 87.50 %、黄河蟹4 1.66%、辽河蟹 10 .83%。这一遗传渐变的度量可作为区别这三个水系的中华绒螯蟹种群的判据 ;(3) 6水系群体内的平均遗传相似度依次为 :辽河蟹 0 .90 8>南流江蟹 0 .897>瓯江蟹和珠江蟹 0 .895>黄河蟹 0 .890 >长江蟹 0 .850 ;6群体间遗传距离及其UPGMA、NJ聚类分析进一步表明 ,南流江蟹、珠江蟹同长江蟹、辽河蟹及黄河蟹在基因组之间存在明显的歧化。 更多还原     

绒螯蟹形态生成特征和放养措施

比较了４种绒螯蟹的形态，介绍了我国中华绒螯蟹六大水系生态群的形态生态特征和放养注意事项。     

南海主要珊瑚礁(鱼旨)科鱼类的组成与分布

1998年3~5月和1999年5~6月,采用手钓、延绳钓和刺网3种作业方式在西沙的浪花礁、华光礁、琛航岛、永兴岛、北礁和南沙的渚碧礁、南薰礁、东门礁、美济礁、赤瓜礁、永署礁、华阳礁等12座珊瑚礁水域进行了2个航次的鱼类资源调查,捕获科鱼类6属25种,渔获量计942尾256.4kg;其中在南沙调查区捕获6属22种,共641尾205.5kg,优势种依次为尾纹九棘鲈、蜂巢石斑鱼、六角石斑鱼、黑边石斑鱼;在西沙调查区捕获6属14种,共301尾50.9kg,优势种依次为尾纹九棘鲈、六角石斑鱼、黑边石斑鱼、蜂巢石斑鱼,同时分析了主要种类尾纹九棘鲈、六角石斑鱼和蜂巢石斑鱼的生物学特征。     

3种沉水植物对夏季高温强光照环境的生理响应

为了研究外来沉水植物伊乐藻（Elodea nuttallii）和埃格草（Egeria densa）对夏季自然高温强光照环境的生理响应,选择同科本地种轮叶黑藻（Hydrilla verticillata）作对比,在2014年8月夏季自然环境下进行实验处理,分别在第0、3、6、9、12、15天测定各物种的叶绿素含量、最大光能转化效率（Fv/Fm）、丙二醛含量和脯氨酸含量,以分析其变化情况。结果显示,高温与强光照对3种沉水植物的生理特征都有显著影响,特别是对其光合作用影响显著,且长期高温强光照环境的影响更大。第1-3天,温度升高至31℃左右,伊乐藻的叶绿素含量和3种植物的Fv/Fm显著低于初始值（P<0.05）;第4-6天温度持续在32℃左右,3种植物的叶绿素含量和Fv/Fm显著低于初始值（P<0.05）,且伊乐藻和埃格草的丙二醛含量显著高于初始值（P<0.05）;除了第3天埃格草的叶绿素含量外,整个实验期间伊乐藻和埃格草的叶绿素含量和Fv/Fm显著低于初始值（P<0.05）,在第12天和第15天时轮叶黑藻的叶绿素含量与初始值无明显差异（P>0.05）,第9天和第12天轮叶黑藻的Fv/Fm与初始值无明显差异（P>0.05）,并且整个实验期间轮叶黑藻的丙二醛含量和脯氨酸含量与初始值均无明显差异（P>0.05）,表明轮叶黑藻通过较快恢复光合作用并维持体内抗氧化系统的稳定,对夏季高温强光照环境展现出较好的适应能力。光合作用能力降低以及长期高温强光照条件下,丙二醛含量显著增加,使得外来种伊乐藻和埃格草不适合在高温强光照环境中生长,夏季高温与强光照环境将会抑制其入侵和扩散。外来种伊乐藻和埃格草对高温强光照的耐受力低于本地种轮叶黑藻。     

Molecular identification of iridoviruses infecting various sturgeon species in Europe

Iridoviridae are known to cause disease in sturgeons in North America. Here, histological and molecular methods were used to screen for this family of virus in sturgeons from various European farms with low‐to‐high morbidity. Some histological samples revealed basophilic cells in the gill and labial epithelia, strongly suggesting the accumulation of iridovirus particles. Newly developed generic PCR tests targeting the major capsid protein (MCP) gene of sturgeon iridoviruses identified in North America, namely the white sturgeon iridovirus and the Namao virus (NV), produced positive signals in most samples from four sturgeon species: Russian (Acipenser gueldenstaedtii), Siberian (A. baerii), Adriatic (A. naccarii) and beluga (Huso huso). The sequences of the PCR products were generally highly similar one another, with nucleotide identities greater than 98%. They were also related to (74–88%), although distinct from, American sturgeon iridoviruses. These European viruses were thus considered variants of a single new virus, provisionally named Acipenser iridovirus‐European (AcIV‐E). Moreover, three samples infected with AcIV‐E showed genetic heterogeneity, with the co‐existence of two sequences differing by five nucleotides. One of our European samples carried a virus distinct from AcIV‐E, but closely related to NV identified in Canada (95%). This study demonstrates the presence of two distinct sturgeon iridoviruses in Europe: a new genotype AcIV‐E and an NV‐related virus.     

Evaluation of genetic diversity of eight grouper species <Emphasis Type="Italic">Epinephelus</Emphasis> spp. based on microsatellite variations

ABSTRACT:   Genetic diversity among eight species of grouper, Epinephelus bleekeri , E. coioides , E. malabaricus , E. ongus , E. akaara , E. maculatus , E. merra and E. fuscoguttatus , was studied using six microsatellite loci, Em-01 *, Em-03 *, Em-07 *, Em-08 *, Em-10 *, and CA-07 *, with the aim of exploring the feasibility of using microsatellite data for species identification. The results showed high levels of genetic differentiation among species ( F _ST  = 0.4403 and R _ST  = 0.4954). Species identification based on fixed allelic differences was possible between E. coioides , E. ongus , and E. fuscoguttatus at Em-01 * and between E. fuscoguttatus and E. ongus at Em-08 *. Private alleles were found in all species, except for E. ongus . Pairwise F _ST ranged 0.238–0.578 ( P  < 0.008 Bonferroni correction), and Nei's genetic distance ranged 0.433–2.710. Size homoplasy was observed at Em-03 * 157 allele, which was characterized by a T–C transition at the 119th nucleotide site of PCR products. The genetic assignment test unambiguously assigned each individual to the correct species. Thus, this test can be used for species identification of unknown individuals when the multilocus genotypes of the six microsatellite loci are available. The phylogenetic (neighbor-joining) tree, which was constructed based on the genetic distance matrix, separated the eight grouper species into two main groups.     

Effects of dietary vitamin E on antioxidant defence mechanisms of juvenile turbot (Scophthalmus maximus L.), halibut (Hippoglossus hippoglossus L.) and sea bream (Sparus aurata L.)

In order to enhance growth, survival and quality during early juvenile stages of marine fish it is important to avoid lipid oxidation problems that are known to cause pathologies and disease. The aim of the present study was to characterize and compare the antioxidant systems in juvenile marine fish of commercial importance in European aquaculture, namely turbot (Scophthalmus maximus), halibut (Hippoglossus hippoglossus) and gilthead sea bream (Sparus aurata). The experiment investigated the interaction of the dietary antioxidant micronutrient, vitamin E, with antioxidant defence systems. Fish were fed with diets of identical unsaturation index supplemented with graded amounts of vitamin E. The relationships between dietary and subsequent tissue vitamin E levels were determined as well as the effects of vitamin E supplementation on lipid and fatty acid compositions of both liver and whole fish, on the activities of the liver antioxidant defence enzymes, and on the levels of liver and whole body lipid peroxidation products, malondialdehyde (thiobarbituric acid reactive substances, TBARS) and isoprostanes. Growth and survival was only significantly affected in sea bream where feeding the diet with the lowest vitamin E resulted in decreased survival and growth. A gradation was observed in tissue vitamin E and polyunsaturated fatty acid (PUFA)/vitamin E levels in response to dietary vitamin E levels in all species. The activities of the main radical scavenging enzymes in the liver, catalase, superoxide dismutase and glutathione peroxidase generally reflected dietary and tissue vitamin E levels being highest in fish fed with the lowest level of vitamin E. The indicators of lipid peroxidation gave consistent results in all three species, generally being highest in fish fed with the unsupplemented diet and generally lowest in fish fed with the diet with highest vitamin E. In this respect, isoprostane levels generally paralleled TBARS levels supporting their value as indicators of oxidative stress in fish. Overall the relationships observed were logical in that decreased dietary vitamin E led to decreased levels of tissue vitamin E, and generally higher activities of the liver antioxidant enzymes and higher levels of lipid peroxides.     

同时检测CSFV、PRRSV的二重RT-PCR方法的建立及其在临床样品检测中的初步应用

建立了1种一步法RT-PCR用于同时检测典型猪瘟病毒(CSFV)和猪繁殖呼吸道综合征病毒(PRRSV)的多重PCR诊断方法(Multiplex PCR,mPCR)。根据Genbank上公布的CSFV、PRRSV基因组全序列及部分序列,借助DNAStar和Oligo6.0基因序列和引物设计软件,设计2对特异性引物分别用于扩增CFSV、PRRSV病毒777bp和434bp的目的片断。该mPCR由RT反应和PCR反应构成。将病毒核酸连接到PMD18-T载体,提取质粒后,以10倍进行倍比稀释,取每个稀释度的病毒核酸进行mPCR反应,对CSFV、PRRSV的最低检测量分别为8.5pg、8.3×10-2pg。以PCV2、PCV1、PPV、PRV、SIV、E.coil和双蒸水为模板进行mPCR反应,扩增结果均为阴性,表明该mPCR具有较好的特异性。对临床样品的检测表明,本研究建立的mPCR诊断方法能够对CSFV和PRRSV进行快速的诊断,同时对CSFV、PRRSV在猪群中的流行病学调查也具有十分重要的意义。     

两种杂交石斑鱼子一代杂种优势的微卫星标记分析

使用6对微卫星引物对两种杂交子一代(青龙斑和虎龙斑)及其亲本(斜带石斑鱼、棕点石斑鱼和鞍带石斑鱼)共5个群体进行微卫星分析,计算等位基因频率、有效等位基因数、基因杂合度、多态信息含量、相似指数和Nei氏遗传距离。结果显示,在5种石斑鱼中,棕点石斑鱼的平均有效等位基因数最大(6.849 3),最小的是鞍带石斑鱼(2.608 6)。6对微卫星引物在这5个群体中具有丰富的多态性,平均多态信息含量(PIC)分别为0.666 7、0.751 3、0.441 9、0.664 0、0.542 6。在平均观测杂合度(Ho)中,虎龙斑和青龙斑的最高均为0.940 0,鞍带石斑鱼的最低为0.508 3。遗传距离和遗传相似率结果显示,青龙斑和虎龙斑均与父本鞍带石斑鱼的亲缘关系较近。杂交子一代群体的等位基因基本来自父母本群体双方,可推断杂交子一代的遗传物质来自父母双方,属两性融合生殖,是真正意义上的杂交种。杂交后代的遗传变异水平明显增强,这是杂种优势得以形成的重要遗传物质基础。     

4种石斑鱼亲缘关系的RAPD分析

采用9个引物,对湛江沿海野生蜂巢石斑鱼、鲑点石斑鱼、点带石斑鱼及黑边石斑鱼的基因组DNA进行了RAPD分析,研究结果表明:蜂巢石斑鱼、鲑点石斑鱼、点带石斑鱼及黑边石斑鱼种间遗传距离(Dij)分别为0 4009(蜂巢石斑鱼-鲑点石斑鱼)、0 4805(蜂巢石斑鱼-点带石斑鱼)、0 5703(蜂巢石斑鱼-黑边石斑鱼)、0 4409(鲑点石斑鱼-点带石斑鱼)、0 4561(鲑点石斑鱼-黑边石斑鱼)及0 4729(点带石斑鱼-黑边石斑鱼);用UPGMA法对这4种石斑鱼进行聚类分析可知,蜂巢石斑鱼与鲑点石斑鱼首先聚在一起(0 4009),而后蜂巢石斑鱼-鲑点石斑鱼与点带石斑鱼聚在一起(0 4611),最后,蜂巢石斑鱼-鲑点石斑鱼-点带石斑鱼再与黑边石斑鱼聚在一起(0 4951)。在所研究的类群中,蜂巢石斑鱼和鲑点石斑鱼有较近的亲缘关系。     

The importance of dietary HUFA for meagre larvae (Argyrosomus regius; Asso, 1801) and its relation with antioxidant vitamins E and C

Despite the interest of meagre (Argyrosomus regius) as a fast‐growing candidate for Mediterranean aquaculture diversification, there is a lack of information on nutrition along larval development. Importance of highly unsaturated fatty acids (HUFA) and the antioxidant vitamins E and vitamin C has not been investigated yet in this species. Six diets with two levels of HUFA (0.4% and 3% dw), two of vitamin E (1500 and 3000 mg kg^?1) and two of vitamin C (1800 and 3600 mg kg^?1) were fed to 15 dah meagre larvae. Larval growth in total length and dry body weight was significantly lowest in larvae fed diet 0.4/150/180 and showed few lipid droplets in enterocytes and hepatocytes and lower HUFA contents than the initial larvae. Increase in dietary HUFA up to 3%, significantly improved larval growth and lipid absorption and deposition. Besides, among fish fed 3% HUFA, increase in vitamin E and vitamin C significantly improved body weight, as well as total lipid, 22:6n‐3 and n‐3 fatty acids contents in the larvae. Thus, the results showed that 0.4% dietary HUFA is not enough to cover the essential fatty acid requirements of larval meagre and a high HUFA requirement in weaning diets is foreseen for this species. Besides, the results also pointed out the importance of dietary vitamin E and C to protect these essential fatty acids from oxidation, increase their contents in the larvae and promote growth, suggesting high vitamin E and C requirements in meagre larvae (higher than 1500 and 1800 mg kg^?1 for vitamin E and vitamin C respectively).     

Limited genetic structure among broad-scale regions for two commercially harvested,tropical deep-water snappers in New Caledonia

We estimated the spatial population connectivity of Etelis carbunculus and E. coruscans based on measures of population genetic structure using the mitochondrial DNA control region. We collected samples from three areas separated by a minimum of 200 km around New Caledonia. We identified two separate genetic groups for E. carbunculus and a single group for E. coruscans. There were many singleton haplotypes distributed among geographic regions, indicating minimal spatial differentiation in genetic structure between regions for each species, although one of the genetic groups for E. carbunculus was in only two of the three regions. Conservation and management directives should consider both species as a single genetic stock among these three widespread regions. Our results provide evidence that stock structure might be less variable in the South Pacific than reported elsewhere, possibly indicating that trans-boundary management may be required in this region for deep-water snapper fisheries. Further refinement (including taxonomy) is required for E. carbunculus to characterize the different lineages observed.