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1.
双须叶须鱼(Ptychobarbus dipogon Regan)隶属裂腹鱼亚科(Schizothoracinae)叶须鱼属(Ptychobarbus),是西藏特有经济鱼类,2016年被列入中国脊椎动物红色名录,必须加快推动该鱼的养护工作。2013年2~3月份及2014年2~6月份,在雅鲁藏布江谢通门段与支流拉萨河上游段采集1 030尾双须叶须鱼样本,以脊椎骨作为年龄鉴定材料进行年龄与生长特点研究,以期分析和评价该类群鱼类资源情况。研究结果如下:双须叶须鱼样本中最大年龄为49龄,最小年龄为4龄;体重与体长关系是样本总体W=4.4×10-5?SL2.7688、雌鱼W=5.0×10-4?SL2.3474、雄鱼W=2.8×10-5?SL2.8414;体长生长方程为雌鱼Lt(♀)=431.8[1-e-0.19t+1.19)],渐进体长L(♀)=431.8 mm,拐点年龄为3.3龄,雄鱼Lt(♂)=367.6[1-e-0.42t+3.37)],渐进体长L(♂)=367.7 mm;体重生长方程为雌鱼Wt(♀)=767.40[1-e-0.19t+1.19)]2.3474,雄鱼Wt(♂)=545.02[1-e-0.42t+3.37)]2.8414;群体异速生长指数b=2.768 8与匀速生长指数3存在显著性差异,即P<0.05。研究表明双须叶须鱼体趋向低龄化,应当予以充分关注。  相似文献   

2.
于2020年10月至2021年3月在四川省甘孜藏族自治州雅砻江江段(雅江县至新龙县)采集厚唇裸重唇鱼(Gymnodiptychus pachycheilus)样本189尾,用以研究雅砻江中游厚唇裸重唇鱼的种群结构与生长特性,分析其野生资源现状、影响因素及保护对策。结果显示雅砻江中游厚唇裸重唇鱼调查种群由3-9龄组成,其中优势年龄组为4-6龄,占样本总数的87.83%;种群平均体长和体重分别为264.1 mm和250.5 g,雌雄性比为1.48:1,雌性和雄性最小性成熟个体年龄均为4龄,对应体长分别为202.0 mm和220.0 mm,对应体重分别为105.0 g和133.0 g;种群的平均肥满度为1.22,体长(L)与体重(W)关系式为W=5.00×10-6L3.146R2=0.948,n=189),属于匀速生长类型;种群体长和体重的Von Bertalanffy生长方程分别为Lt=727.5[1-e-0.097(t-0.508)],Wt=5224.9[1-e-0.097(t-0.508)]3.146;生长拐点年龄为12.4龄,对应的体长和体重分别为505.2 mm和1568.3 g。研究表明目前雅砻江中游厚唇裸重唇鱼表现出年龄结构趋于低龄化,体型趋于小型化的种群结构特点,且具有自然寿命较长、生长缓慢、渐近体长较大等生长特性,加之雅砻江饵料基础和水文条件较差等因素,推测雅砻江中游厚唇裸重唇鱼所具备的种群增长潜力较低,其野生资源的自然恢复面临挑战。因此,应尽快开展雅砻江流域厚唇裸重唇鱼野生资源的保护工作。  相似文献   

3.
细肢新米虾(Neocaridina gracilipoda)是中国常见淡水虾类之一,在水域生态系统中起重要的作用(如在物质循环和能量流动中起链接作用),但有关其基础生物学方面的研究目前却鲜见报道。有鉴于此,于2022年秋季在赤水河流域青菜河水库坝下(106°07′52″E,27°36′12″N)采集细肢新米虾490尾,通过对样本体长与体重的测定,掌握了此虾的体长和体重分布并报道了该物种的体长-体重关系。研究结果如下,青菜河水库坝下细肢新米虾:(1)体长介于10.60~32.13 mm(19.67 ± 2.54 mm)之间,优势体长集中在16.50~22.50 mm(n = 390,占总丰度的79.59%);(2)体重介于0.01~0.44 g(0.11 ± 0.04 g)之间,优势体重集中在0.05~0.15 g(n = 415,占总丰度的84.69%);(3)体长-体重的关系为W = 4 × 10-5L2.66R2 = 0.78,n = 490),b值(b = 2.66)与3存在显著性差异(P < 0.05),即表明青菜河水库坝下细肢新米虾种群呈负异速生长。  相似文献   

4.
根据2015、2018—2020年瓯江口水域渔业资源监测调查资料, 对1359尾凤鲚的体长、全长和体重等生物学信息进行测定, 利用体长频率分布估算凤鲚种群生长、死亡参数等。结果表明, 瓯江口凤鲚体长为5.2—21.9 cm; 体长和体重的关系式W=0.0035×L3.0783。用ELEFAN技术拟合的von Bertalanffy生长方程的各参数为L=26.60 cm, k=0.47及t0=–0.55 a; Z=2.30, M=1.00, F=1.30, E=0.567, 表明资源处于过度开发状态; 凤鲚的首次捕捞体长Lc=15.35 cm, 对应首次捕捞平均年龄为1.28 a, 小于临界年龄(1.36 a)和体重生长的拐点年龄(1.85 a), 表明当前渔业主要捕捞对象为幼鱼和补充群体, 无法保证资源的有效补充。在瓯江口凤鲚目前的资源状态下, 应努力降低捕捞死亡率, 并加强对凤鲚栖息环境的保护, 而对目前以小型化和低龄化为主的凤鲚群体, 以控制开捕体长为主, 根据Beverton-Holt动态模型, 建议开捕体长为15.50 cm, 对应开捕年龄为1.31 a。  相似文献   

5.
本研究运用多变量路径分析技术,分析饥饿7d (饥饿组)和非饥饿状态下(对照组)眼斑双锯鱼(Amphiprion ocellaris)幼鱼的体质量和形态特征之间的相互依赖关系。实验对两种状态下的幼鱼进行体质量(g)和全长(L1)、体长(L2)、体高(L3)、头长(L4)、头高(L5)、吻长(L6)、尾柄长(L7)、尾柄高(L8)、背鳍前距(L9)、胸鳍前距(L10)、腹鳍前距(L11)、臀鳍前距(L12)、眼径(L13)等13个形态性状(mm)的准确测定。采用相关系数、决定系数、通径系数和回归方程等统计方法分析两种状态下眼斑双锯鱼幼鱼的形态性状对体质量的影响。结果显示,两个实验组14个性状间均存在极显著相关关系(P<0.01);剔除共线性影响后,通径分析筛选出了对照组对体质量影响显著的4个形态性状,直接作用由大到小排序:L3 > L2 > L6 > L5,间接作用由大到小排序:L5 > L6 > L2 > L3,单独决定系数由大到小排序:L3 > L2 > L5 > L6;饥饿组筛选出5个形态性状,直接作用由大到小是L3 > L2 > L12 > L6 > L7,间接作用由大到小是L7 > L12 > L2 > L6 > L3,单独决定系数由大到小为L3 > L2 > L12 > L7 > L6;对照组和饥饿组体质量与形态性状的多元回归方程分别为:W=-0.819+0.106L3+0.027L2+0.006L6-0.050L5,R2=0.94;W=-0.778+0.078L3+0.016L12+0.015L2-0.055L7+0.018L6,R2=0.930。结果表明,饥饿影响了形态性状与体质量的相关性,但饥饿和非饥饿状态下体高、体长和吻长都是影响体质量的关键因子,其中体高是最主要的因子,该结果可在眼斑双锯鱼的选育工作中对选育指标的确定提供理论支持。  相似文献   

6.
为赋予单链尿激酶型纤溶酶原激活剂(single chain urokinase-type plasminogen activator, scu-PA, 尿激酶原)以抗血小板聚集的功能,在scu-PA的kringle区118位Gly与119位Leu之间插入PRGDWR序列(insert mutant B,InB).利用甲醇酵母(Pichia pastoris)进行分泌表达,经金属离子螯合亲和层析与S强阳离子交换层析,得到纯蛋白.实验测定InB对人工合成底物S-2444的酰胺解活性为5 900 IU/mg,动力学常数为:Km,S-2444InB=56.8 μmol·L-1,kcat,S-2444InB=0.33 s-1;水解天然底物plasminogen的动力学常数为:Km,plgInB=0.397 μmol·L-1,kcat,plgInB=0.0164 s-1.InB激活plasminogen的反应在有fibrin存在条件下InB的活性为无fibrin条件下的46.3%.该突变体在体外激活plasminogen的活性与同一系统表达的野生型scu-PA基本相同.该突变体表现出较强的抗血小板聚集活性,IC50=12.7 μmol·L-1,而野生型scu-PA无此功能.实验表明scu-PA的K区插入突变体InB是一种极具潜力的双功能溶栓分子.  相似文献   

7.
[目的] 研究稻虾共作模式条件下,稻田封闭除草剂对克氏原螯虾产生的急性毒性。[方法] 采用半静态试验方法,研究3种酰胺类除草剂(乙草胺、丙草胺和丁草胺)对克氏原螯虾的急性毒性,计算3种酰胺类除草剂对克氏原螯虾的安全浓度,并分析其LC50衰减规律。[结果] 随着暴露时间和除草剂浓度的增加,虾体侧躺,步行足和游泳足活动频率降低,最终死亡。乙草胺对克氏原螯虾的96 h半致死浓度(LC50)和安全浓度(SC)分别为0.0707和0.0146 mL·L-1;丙草胺对克氏原螯虾的96 h LC50和SC分别为0.0119和0.0021 mL·L-1;丁草胺对克氏原螯虾的96h LC50和SC分别为0.0073和0.0014 mL·L-1。乙草胺、丙草胺及丁草胺除草剂LC50随着暴露时间延长呈下降趋势,符合双曲线衰减模型,回归方程分别为:① y1=2.0840x-0.7380R2=0.9973);② y2=0.1106x-0.4930R2=0.9872);③ y3=0.2236x-0.7480R2=0.9990)。克氏原螯虾对3种除草剂的敏感性由高到低依次为:丁草胺 > 丙草胺 > 乙草胺。[结论] 乙草胺和丙草胺可在稻田综合种养生产过程中按常规剂量使用,而丁草胺按常规剂量使用可能存在较大的风险。  相似文献   

8.
为了解同域分布有蹄类在环境复杂的山地森林生境中以何种方式维持种间关系以实现稳定共存,基于物种分布模型与日活动模式分析了四川省岷山、邛崃、大相岭、小相岭和凉山五大山系同域分布中华鬣羚(Capricornis milneedwardsii)与中华斑羚(Naemorhedus griseus)的时空生态位特征。结果显示:(1)在四川省五大山系,中华鬣羚的适宜栖息地面积为28006.07 km2,占研究区总面积的26.18%,其中高适宜栖息地面积为10015.90 km2,中华斑羚的适宜栖息地面积为21073.32 km2,占研究区总面积的19.71%,其中高适宜栖息地面积为8396.22 km2;(2)中华鬣羚与中华斑羚在生境因子选择上相似性高、栖息地重叠面积大,其空间生态位重叠度指数D=0.776,I=0.949,其适宜栖息地的主要重叠区域位于岷山和邛崃山系;(3)中华鬣羚与中华斑羚的日活动节律重叠指数为0.812;(4)中华鬣羚与中华斑羚属于同域分布的资源利用型竞争物种,中华鬣羚的存在会显著影响中华斑羚的日活动节律(P=0.016);二者同域分布时都会增加其昼间活动强度,并增加活动高峰期的强度及持续时间。本研究初步分析了中华鬣羚与中华斑羚的时空生态位特征,揭示了二者在空间、时间生态位上种群共存及种间竞争的耦合关系。研究有利于深入理解同域分布动物时空生态位特征、近缘物种的共存机制及种间竞争关系,为有蹄类等珍稀野生动物种群及栖息地的保护提供科学参考。  相似文献   

9.
淀山湖刀鲚的生物学参数估算及其相对单位补充量渔获量   总被引:2,自引:0,他引:2  
刀鲚是淀山湖水域内资源丰度最高的鱼类,在该湖泊的生态系统中处于重要地位.本文根据2010年7月至2011年8月在淀山湖水域采集的3107尾刀鲚的长度频率数据,利用ELEFAN I技术对刀鲚的生长和死亡参数进行估算,并根据Beverton-Holt动态综合模型评估刀鲚资源变动趋势.结果表明:von Bertalanffy生长方程描述的刀鲚生长参数为L∞=35.70cm,k=0.54,t0=-0.48 a,体质量的生长拐点年龄为1.37 a.采用Pauly经验公式估算出刀鲚的自然死亡系数M=0.872.采用长度变换渔获曲线法估算刀鲚的总死亡系数Z=2.121,捕捞死亡系数F=1.249,当前开发率E=0.589,表明资源已处于过度开发状态.根据Beverton-Holt动态综合模型,建议最适的开捕体长应为21.42 cm,对应开捕年龄为1.22 a.  相似文献   

10.
全球性生物多样性保护与利用正逐步走向高质量发展,拥有丰富物种资源已成为夺取生物科技制高点的关键,因此,贵州稀有濒危种子植物多样性保护与利用的研究具有重要意义。在对贵州稀有濒危种子植物资源调查的基础上,选取具有重要应用价值的小黄花茶(Camellia luteoflora)、贵州红山茶(C. kweichowensis)等103种贵州稀有濒危植物,采用模式标本产地植物追溯、现存分布区及种群散布特征调查、物种濒危等级评估、混合采种迁地保育、生物资源测试分析与资源评价相结合的方法,开展了植物物种多样性编目及其迁地保护、种子生物学特性与种子散布及分布动态变化、种苗繁育与应用栽培试验等研究。结果表明:(1)调查评估的103种贵州稀有濒危种子植物都采取了就地保护措施,但迄今为止对濒危威胁程度减轻的效应不明显,抢救性迁地保护依然必要,其中极危(CR)23种、濒危(EN)30种、易危(VU)40种、近危(NT)7种、无危(LC)3种; 采用同一地理种源迁地保护有效种群PnLf·Ee·Am的栽培方法,在贵州省植物园开展了迁地保护引种栽培试验。其中,国家重点保护野生植物33种、3 650株,引种栽培平均成活率为95.47%,贵州及毗邻川、滇、桂极少数地区特有分布的种子植物70种、11 010株,引种栽培平均成活率为95.80%,并且建成了活植物保育圃30 200 m2。(2)搜集文献大数据结合GIS信息追踪调查研究,发现了小黄花茶新分布区2.5 km2、长柱红山茶(C. longistyla)新分布区1.5 km2、美丽红山茶(C. delicata)新分布区1.0 km2、皱叶瘤果茶(C. rhytidophylla)新分布区6.0 km2、红花瘤果茶(C. rubituberculata)新分布区50.0 km2、贵州槭(Acer guizhouensis)新分布区0.3 km2; 新分布区种群增量对其减轻濒危程度的评估效果影响不明显。(3)选择了小黄花茶、贵州红山茶等20种具有贵州高原区域环境特色的经济植物开展了种苗繁育和应用栽培试验,建立种苗繁育基地13.4 hm2,繁育种苗73万余株,在林业绿化工程应用中示范栽培140.0 hm2(31万株),≥2年生苗木应用栽培存活率92.00%~98.00%,这为有关稀有濒危植物的科学研究及种质创新利用提供科学参考。  相似文献   

11.
Functionally active preparations of Na+,K+-ATPase isozymes from calf brain that contain catalytic subunits of three types (1, 2, and 3) were obtained using two approaches: a selective removal of contaminating proteins by the Jorgensen method and a selective solubilization of the enzyme with subsequent reconstitution of their membrane structure by the Esmann method. The ouabain inhibition constants were determined for the isozymes. The real isozyme composition of the Na+ pump from the grey matter containing glial cells and the brain stem containing neurons was determined. The plasma membranes of glial cells were shown to contain mainly Na+,K+-ATPase of the 11 type and minor amounts of isozymes of the 22(1) and the 31(2) type. The axolemma contains 21 and 31 isozymes. A carbohydrate analysis indicated that 11 enzyme preparations from the brain grey matter substantially differ from the renal enzymes of the same composition in the glycosylation of the 1 isoform. An enhanced sensitivity of the 3 catalytic subunit of Na+,K+-ATPase from neurons to endogenous proteolysis was found. A point of specific proteolysis in the amino acid sequence PNDNR492 Y493 was localized (residue numbering is that of the human 3 subunit). This sequence corresponds to one of the regions of the greatest variability in 1-, 2-, 3-, and 4-subunits, but at the same time, it is characteristic of the 3 isoforms of various species. The presence of the 3 isoform of tubulin (cytoskeletal protein) was found for the first time in the high-molecular-mass Na+,K+-ATPase 31 isozyme complex isolated from the axolemma of brain stem neurons, and its binding to the 3 catalytic subunit was shown.  相似文献   

12.
The chemical structure of lipid A, from the marine -proteobacterium Pseudoalteromonas haloplanktis 14393, a main product of lipopolysaccharide hydrolysis (1% AcOH), was determined using chemical methods and NMR spectroscopy. The lipid A was shown to be -1,6-glucosaminobiose 1,4-diphosphate acylated with two (R)-3-hydroxyalkanoic acid residues at C3 and C3 and amidated with one (R)-3-hydroxydodecanoyl and one (R)-3-dodecanoyloxydodecanoyl residue at N2 and N2, respectively.  相似文献   

13.
Two burgeoning research trends are helping to reconstruct the evolution of the Hox cluster with greater detail and clarity. First, Hox genes are being studied in a broader phylogenetic sampling of taxa: the past year has witnessed important new data from teleost fishes, onychophorans, myriapods, polychaetes, glossiphoniid leeches, ribbon worms, and sea anemones. Second, commonly accepted notions of animal relationships are being challenged by alternative phylogenetic hypotheses that are causing us to rethink the evolutionary relationships of important metazoan lineages, especially arthropods, annelids, nematodes, and platyhelminthes.  相似文献   

14.
Komárek has recently reviewed the various species assigned to the green algal genusNeochloris Starr (Chlorococcales, Chlorococcaceae) and removed those with uninucleate vegetative cells to a new genus,Ettlia. Watanabe & Floyd, unaware ofKomárek's work, also reviewed the species ofNeochloris and distributed them among three genera—Neochloris, Chlorococcopsis gen. nov., andParietochloris gen. nov.—on the basis of details of the covering of the zoospore and the arrangement of the basal bodies of the flagellar apparatus. This paper reconciles these two treatments and makes additional recommendations at the ranks of genus, family, order, and class.  相似文献   

15.
Neutral glycolipids from the brain of a patient with Fucosidosis were analyzed and two complex glycolipids containing five and eight sugars were isolated from the cortical grey matter. These two glycolipids reacted with antibodies recognizing the SSEA-1 [Lex(X)] carbohydrate determinant. SSEA-1 glycolipids are normally expressed in human embryonic brain but are found in only small amounts in postnatal human brain. The accumulation of the two SSEA-1 glycolipids in Fucosidosis brain thus represents a defect which affects the normal developmentally regulated decrease in postnatal, expression of these glycolipids, and may be a contributing factor in the abnormal brain development associated with the disease. Chemical characterization of the two isolated glycolipids by gas chromatographic and mass spectrometric analyses has identified the two glycolipids as lacto-N-fucopentaosylceramide (III) and difucosyl-neolactonorhexaosylceramide.Abbreviations DCl direct chemical ionization - FAB tastatiom bombardment - GC gas chromatography - GSLs glycosphingolipids - MS mass spectrometry - SSEA-1 stage specific embryonic antigen-1 - TLC thin layer chromatographys  相似文献   

16.
17.
The progeny of Herpes simplex virus type 1 (HSV-1) grown in ricin-resistant 14 cells (RicR14) lackingN-acetylglucosaminyltransferase I was released in the extracellular medium at a very low rate. By using a monoclonal antibody immobilized on Sepharose we purified from HSV-1-infected RicR14 cells a viral glycoprotein (gC), which carries bothN-andO-linked oligosaccharides. Glycopeptides obtained from [3H]mannoselabeled gC by Pronase digestion were entirely susceptible to endo--N-acetylglucosaminidase H, and the major oligosaccharide released was Man4GlcNAc. The accumulation of this high-mannose species was related to the enzymic defect of the host cells and to the long retention of the viral glycoprotein within the cells. The extent ofO-glycosylation evaluated in [14C]glucosamine-labeled gC from RicR14 cells as compared to that of gC from wild type cells did not appear to be significantly modified.Abbreviations Con A concanavalin A - BHK cells baby hamster kidney cells - HSV Herpes simplex virus  相似文献   

18.
19.
Systematic significance of mature embryo of bamboos   总被引:1,自引:0,他引:1  
The mature embryo of seven species belonging to five genera of Indian bamboos is described. In all these the basic pattern of embryo organisation is same: the scutellar and coleoptilar bundles are not separated by an internode, the epiblast is absent, the lower portion of the scutellum and the coleorhiza are separated by a cleft and the margins of embryonic leaves overlap. The features unique to fleshy fruited bamboos are: presence of a massive scutellum, the juxtaposition of plumule and radicle and the occurrence of a bud in the axil of the coleoptile. The fleshy fruit bearing bamboos should be classified into one group, the tribeMelocanneae. Evidence is provided to recognise additional groups in the subfamilyBambusoideae.  相似文献   

20.
The Drosophila Pax6 homolog twin of eyeless (toy) is so far the first zygotically expressed gene involved in eye morphogenesis in Drosophila. The study of its expression during embryogenesis is therefore informative of the initial events of eye development in Drosophila. We have analyzed how the initial expression domain of toy at cellular blastoderm is regulated. We show that the three maternal patterning systems active in the cephalic region (the anterior, terminal and dorsal-ventral systems) cooperate with zygotically activated gap genes to shape the initial expression domain of toy. Whereas Bicoid, Dorsal and Torso signaling synergistically act as activators, Hunchback, Knirps and Decapentaplegic act as repressors.  相似文献   

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